diff --git a/mobile/app/src/main/java/com/odweta/solen/MainActivity.kt b/mobile/app/src/main/java/com/odweta/solen/MainActivity.kt
index 2eee385..7001092 100644
--- a/mobile/app/src/main/java/com/odweta/solen/MainActivity.kt
+++ b/mobile/app/src/main/java/com/odweta/solen/MainActivity.kt
@@ -1,75 +1,184 @@
 package com.odweta.solen
 
-import android.annotation.SuppressLint
 import android.graphics.ImageDecoder
 import android.graphics.drawable.AnimatedImageDrawable
-import android.os.Build
 import android.os.Bundle
 import android.util.Log
 import android.view.Menu
 import android.view.MenuItem
 import android.view.View
-import android.webkit.WebResourceError
-import android.webkit.WebResourceRequest
-import android.webkit.WebView
-import android.webkit.WebViewClient
+import android.widget.Button
+import android.widget.EditText
 import android.widget.ImageView
-import android.widget.Toolbar
-import androidx.annotation.RequiresApi
+import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import androidx.lifecycle.lifecycleScope
-import com.bumptech.glide.Glide
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import okhttp3.FormBody
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import org.json.JSONException
 import org.json.JSONObject
+import java.io.File
 import java.io.IOException
+import java.nio.charset.Charset
 import java.time.LocalDateTime
 import java.time.format.DateTimeFormatter
 
-
 class MainActivity : AppCompatActivity(), MainActivityListener {
     companion object {
         val dayMap = mutableMapOf<Int, Day>()
         var days = listOf<Day>()
     }
 
+    private val accountDataFilePath: String = "account_data.txt"
+
     private val client = OkHttpClient()
 
-    private val username = "USERNAME"
-    private val password = "PASSWORD"
+    private lateinit var username: String
+    private lateinit var password: String
     private val apiBaseUrl = "https://aplikace.skolaonline.cz/solapi/api"
     private val tokenUrl = "$apiBaseUrl/connect/token"
-    private var token = ""
+    private lateinit var token: String
     private val userDataUrl = "$apiBaseUrl/v1/user"
-    private var userData = ""
-    private var studentId = ""
+    private lateinit var userData: String
+    private lateinit var studentId: String
     private val timeTableUrl = "$apiBaseUrl/v1/timeTable"
     //private val marksUrl = "$apiBaseUrl/v1/students/$studentId/marks/list"
 
     private suspend fun setupAPI() {
         return withContext(Dispatchers.IO) {
             //Log.d("debug", "setting up API...")
-            token = getToken()
+            token = JSONObject(getToken()).get("access_token").toString()
             if (token == "") {
                 return@withContext
             }
             userData = getUserDataJSON()
             studentId = getStudentId()
+            //Log.d("debug", "API set up!")
         }
     }
 
-    @SuppressLint("MissingInflatedId")
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        setContentView(R.layout.activity_splash_screen)
-
-        setSupportActionBar(findViewById(R.id.toolbar))
+        showSplashScreen()
 
         lifecycleScope.launch {
+            launch()
+        }
+    }
+
+    // Override onCreateOptionsMenu to handle menu item clicks
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        menuInflater.inflate(R.menu.menu_main, menu)
+        return true
+    }
+
+    private fun showSignInScreen() {
+        setContentView(R.layout.activity_sign_in)
+        setSignInButtonOnClick()
+    }
+
+    private fun showSettingsScreen() {
+        setContentView(R.layout.activity_settings)
+        findViewById<Button>(R.id.settingsBackButton).setOnClickListener {
+            launchPhase1()
+        }
+    }
+
+    private fun setSignInButtonOnClick() {
+        findViewById<Button>(R.id.signInButton).setOnClickListener {
+            onSignIn()
+        }
+    }
+
+    // Override onOptionsItemSelected to handle menu item clicks
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        when (item.itemId) {
+            R.id.item_refresh -> {
+                lifecycleScope.launch {
+                    launch()
+                }
+                return true
+            }
+            R.id.item_sign_in -> {
+                showSignInScreen()
+                return true
+            }
+            R.id.item_settings -> {
+                showSettingsScreen()
+                return true
+            }
+            R.id.item_sign_out -> {
+                clearAccountFile()
+                showSignInScreen()
+                return true
+            }
+        }
+
+        return super.onOptionsItemSelected(item)
+    }
+
+    private fun clearAccountFile() {
+        val file = File(applicationContext.filesDir, accountDataFilePath)
+        file.delete()
+        file.createNewFile()
+    }
+
+    override fun onLaunch(view: View) {
+        launch()
+    }
+
+    private suspend fun accountIsValid(acc: Account): Boolean {
+        return withContext(Dispatchers.IO) {
+            username = acc.username
+            password = acc.password
+
+            val token = getToken()
+            //Log.d("debug", "token: '$token'")
+            !JSONObject(token).has("error")
+        }
+    }
+
+    private fun onSignIn() {
+        //Log.d("debug", "onSignIn called!")
+
+        val acc = Account(
+            findViewById<EditText>(R.id.usernameField).text.toString(),
+            findViewById<EditText>(R.id.passwordField).text.toString(),
+            0
+        )
+
+        showSplashScreen()
+
+        saveAccount(acc)
+
+        lifecycleScope.launch {
+            val valid = accountIsValid(acc)
+            //Log.d("debug", "account valid? $valid")
+            //Log.d("debug", acc.username)
+            //Log.d("debug", acc.password)
+
+            if (valid) {
+                launch()
+            } else {
+                showSignInScreen()
+                Toast.makeText(
+                    applicationContext,
+                    "Neplatné přihlašovací údaje, zkuste to znovu",
+                    Toast.LENGTH_LONG
+                ).show()
+            }
+            //Log.d("debug", "onSignIn finished!")
+        }
+    }
+
+    private fun showSplashScreen() {
+        lifecycleScope.launch {
+            setContentView(R.layout.activity_splash_screen)
+
             // Assuming you have an ImageView with ID "animatedImageView" in your layout
             val animatedImageView: ImageView = findViewById(R.id.loading_gif)
 
@@ -83,63 +192,109 @@ class MainActivity : AppCompatActivity(), MainActivityListener {
                 animatedImageView.setImageDrawable(drawable)
                 drawable.start() // Start the animation
             }
+        }
+    }
 
+    class Account(val username: String, val password: String, val error: Int)
+
+    private fun parseAccountDataFile(file: File): Account {
+        val lines: List<String> = file.readLines()
+
+        if (lines.size >= 2) {
+            if (lines[0] != "" && lines[1] != "") {
+                return Account(lines[0], lines[1], 0)
+            }
+        }
+
+        return Account("", "", 1)
+    }
+
+    private fun haveSavedAccount(): Boolean {
+        /* check if a file exists
+         *   no -> create it and return false
+         *   yes -> read the contents and use them as the username and password
+         */
+
+        // check if file exists
+        val file = File(applicationContext.filesDir, accountDataFilePath)
+
+        return if (!file.exists()) {
+            // it does not exist
+            file.createNewFile()
+            false
+        } else {
+            //Log.d("debug", "account file found")
+            // it exists, so it shall be parsed
+            val acc: Account = parseAccountDataFile(file)
+            username = acc.username
+            password = acc.password
+            acc.error == 0
+        }
+    }
+
+    private fun saveAccount(acc: Account): Boolean {
+        return try {
+            val file = File(applicationContext.filesDir, accountDataFilePath)
+            file.writeText("${acc.username}\n${acc.password}\n", Charset.forName("UTF-8"))
+
+            true
+        } catch (e: Exception) {
+            false
+        }
+    }
+
+    private fun launchPhase1() {
+        var week: List<Day>
+        showSplashScreen()
+        lifecycleScope.launch {
             setupAPI()
-            launch()
+            week = parseJSON(getTimeTableJSON())
+
+            launchPhase2(week)
         }
     }
 
-    // Override onCreateOptionsMenu to handle menu item clicks
-    override fun onCreateOptionsMenu(menu: Menu): Boolean {
-        menuInflater.inflate(R.menu.menu_main, menu)
-        return true
-    }
-
-    // Override onOptionsItemSelected to handle menu item clicks
-    override fun onOptionsItemSelected(item: MenuItem): Boolean {
-        when (item.itemId) {
-            R.id.item_refresh -> {
-                lifecycleScope.launch {
-                    launch()
-                }
-                return true
-            }
-            R.id.item_sign_in -> {
-                // TODO: IMPLEMENT
-                return true
-            }
-            R.id.item_settings -> {
-                // TODO: IMPLEMENT
-                return true
-            }
+    private fun launchPhase2(week: List<Day>) {
+        days = week
+        for ((i, day) in week.withIndex()) {
+            //Log.d("debug", "$i, ${day.name}\n${day.date}\n${day.subjects}")
+            dayMap[i] = day
         }
 
-        return super.onOptionsItemSelected(item)
+        setContentView(R.layout.activity_main)
+
+        val toolbar = findViewById<androidx.appcompat.widget.Toolbar>(R.id.toolbar)
+        setSupportActionBar(toolbar)
+        toolbar.title = ""
+        toolbar.inflateMenu(R.menu.menu_main)
+
+        val mainFragment = CalWeekFragment()
+        supportFragmentManager.beginTransaction()
+            .replace(R.id.fragmentContainer, mainFragment)
+            .commit()
     }
 
-    @RequiresApi(Build.VERSION_CODES.O)
-    override fun onLaunch(view: View) {
-        launch()
-    }
-
-    @RequiresApi(Build.VERSION_CODES.O)
     private fun launch() {
         lifecycleScope.launch {
-            setContentView(R.layout.activity_loading_with_bar)
+            /* check if there is a saved user account
+             * if yes, use that
+             * otherwise show the login activity
+             */
 
-            val week = parseJSON(getTimeTableJSON())
-            days = week
-            for ((i, day) in week.withIndex()) {
-                //Log.d("debug", "$i, ${day.name}\n${day.date}\n${day.subjects}")
-                dayMap[i] = day
+            val accSaved: Boolean = haveSavedAccount()
+            //val valid: Boolean = accountIsValid(Account(username, password, 0))
+
+            //Log.d("debug", "username: $username")
+            //Log.d("debug", "password: $password")
+            //Log.d("debug", "saved? $accSaved")//; valid? $valid")
+
+            if (!accSaved) {
+                //Log.d("debug", "showing sign in screen")
+                showSignInScreen()
+            } else {
+                //Log.d("debug", "launching timetable")
+                launchPhase1()
             }
-
-            setContentView(R.layout.activity_main)
-
-            val mainFragment = CalWeekFragment()
-            supportFragmentManager.beginTransaction()
-                .replace(R.id.fragmentContainer, mainFragment)
-                .commit()
         }
     }
 
@@ -163,17 +318,22 @@ class MainActivity : AppCompatActivity(), MainActivityListener {
                 val resp = client.newCall(request).execute()
                 val respString = resp.body?.string()
                 val respJson = respString?.let { JSONObject(it) }
-                val token = respJson?.get("access_token").toString()
-                token
+                respJson.toString()
+            } catch (e: JSONException) {
+                """{"error": "json"}"""
             } catch (e: Exception) {
+                //e.printStackTrace()
                 """{"error": "network"}"""
             }
         }
     }
 
     private fun getStudentId(): String {
-        //Log.d("debug", userData)
-        return JSONObject(userData).get("personID").toString()
+        return if (!userIsParent()) {
+            JSONObject(userData).get("personID").toString()
+        } else {
+            JSONObject(userData).getJSONArray("children").getJSONObject(0).get("id").toString()
+        }
     }
 
     private suspend fun getUserDataJSON(): String {
@@ -187,21 +347,36 @@ class MainActivity : AppCompatActivity(), MainActivityListener {
 
             try {
                 val resp = client.newCall(request).execute()
-                resp.body?.string().toString()
+                val respString = resp.body?.string().toString()
+                //Log.d("debug", "userData: $respString")
+                respString
             } catch (e: IOException) {
                 """{"error": "network"}"""
             }
         }
     }
 
+    private fun userIsParent(): Boolean {
+        return if (userData != "") JSONObject(userData).get("userType").toString() == "parent"
+        else false
+    }
+
     private suspend fun getTimeTableJSON(): String {
         // I now figured out how to use the SOL API (kinda), yay
 
         //Log.d("debug", "getting timetable")
 
         return withContext(Dispatchers.IO) {
+            val userIsParent = userIsParent()
+            //Log.d("debug", "userIsParent? $userIsParent")
+            var url = timeTableUrl
+            if (userIsParent) {
+                url += "?studentId=$studentId"
+            }
+            //Log.d("debug", "url: $url")
+
             val request = Request.Builder()
-                .url(timeTableUrl)
+                .url(url)
                 .header("Content-Type", "application/x-www-form-urlencoded")
                 .header("Authorization", "Bearer $token")
                 .get()
@@ -209,16 +384,15 @@ class MainActivity : AppCompatActivity(), MainActivityListener {
 
             try {
                 val resp = client.newCall(request).execute()
-                //Log.d("d", resp.body?.string().toString())
-                //Log.d("d", JSONObject(resp.body?.string().toString()).get("subject").toString())
-                resp.body?.string().toString()
+                val respString = resp.body?.string().toString()
+                //Log.d("debug", "timetable: $respString")
+                respString
             } catch (e: IOException) {
                 """{"error": "network"}"""
             }
         }
     }
 
-    @RequiresApi(Build.VERSION_CODES.O)
     private fun parseJSON(jsonString: String): List<Day> {
         val jsonObject = JSONObject(jsonString)
 
@@ -231,7 +405,7 @@ class MainActivity : AppCompatActivity(), MainActivityListener {
         val week = mutableListOf<Day>()
 
         if (jsonObject.has("error")) {
-            Log.d("debug error", "network")
+            //Log.d("debug error", "network")
             return week
         }
         //Log.d("debug", "no network error\n\n$jsonString")
diff --git a/mobile/app/src/main/res/layout/activity_main.xml b/mobile/app/src/main/res/layout/activity_main.xml
index 0fb28ca..e524e81 100644
--- a/mobile/app/src/main/res/layout/activity_main.xml
+++ b/mobile/app/src/main/res/layout/activity_main.xml
@@ -10,8 +10,9 @@
     <com.google.android.material.appbar.AppBarLayout
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
-        android:theme="@style/Theme.Solen.AppBarOverlay"
-        android:fontFamily="@font/roboto_src">
+        android:layout_marginBottom="675dp"
+        android:fontFamily="@font/roboto_src"
+        android:theme="@style/Theme.Solen.AppBarOverlay">
 
         <androidx.appcompat.widget.Toolbar
             android:id="@+id/toolbar"
diff --git a/mobile/app/src/main/res/layout/activity_settings.xml b/mobile/app/src/main/res/layout/activity_settings.xml
new file mode 100644
index 0000000..50e8d9d
--- /dev/null
+++ b/mobile/app/src/main/res/layout/activity_settings.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <Button
+        android:id="@+id/settingsBackButton"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="8dp"
+        android:layout_marginTop="8dp"
+        android:layout_marginEnd="315dp"
+        android:layout_marginBottom="675dp"
+        android:text="Zpět"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/mobile/app/src/main/res/layout/activity_sign_in.xml b/mobile/app/src/main/res/layout/activity_sign_in.xml
new file mode 100644
index 0000000..02009b4
--- /dev/null
+++ b/mobile/app/src/main/res/layout/activity_sign_in.xml
@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <EditText
+        android:id="@+id/usernameField"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="16dp"
+        android:layout_marginBottom="16dp"
+        android:ems="10"
+        android:hint="Uživatelské jméno"
+        android:inputType="text"
+        app:layout_constraintBottom_toTopOf="@+id/passwordField"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintHorizontal_bias="0.0"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <EditText
+        android:id="@+id/passwordField"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="16dp"
+        android:layout_marginBottom="16dp"
+        android:ems="10"
+        android:hint="Heslo"
+        android:inputType="textPassword"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/usernameField" />
+
+    <Button
+        android:id="@+id/signInButton"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="137dp"
+        android:layout_marginTop="72dp"
+        android:layout_marginEnd="137dp"
+        android:layout_marginBottom="88dp"
+        android:text="Přihlásit se"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/passwordField" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
diff --git a/mobile/app/src/main/res/menu/menu_main.xml b/mobile/app/src/main/res/menu/menu_main.xml
index a098aa5..cf4f16b 100644
--- a/mobile/app/src/main/res/menu/menu_main.xml
+++ b/mobile/app/src/main/res/menu/menu_main.xml
@@ -1,14 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android">
-    <item
-        android:id="@+id/item_settings"
-        android:icon="@android:drawable/ic_menu_manage"
-        android:title="@string/settings" />
     <item
         android:id="@+id/item_sign_in"
         android:title="@string/sign_in" />
+    <item
+        android:id="@+id/item_sign_out"
+        android:title="@string/sign_out" />
     <item
         android:id="@+id/item_refresh"
         android:icon="@android:drawable/ic_popup_sync"
         android:title="@string/refresh" />
+    <item
+        android:id="@+id/item_settings"
+        android:icon="@android:drawable/ic_menu_manage"
+        android:title="@string/settings" />
 </menu>
\ No newline at end of file
diff --git a/mobile/app/src/main/res/values/refs.xml b/mobile/app/src/main/res/values/refs.xml
new file mode 100644
index 0000000..a6b3dae
--- /dev/null
+++ b/mobile/app/src/main/res/values/refs.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources></resources>
\ No newline at end of file
diff --git a/mobile/app/src/main/res/values/strings.xml b/mobile/app/src/main/res/values/strings.xml
index a97f3b6..bd8e157 100644
--- a/mobile/app/src/main/res/values/strings.xml
+++ b/mobile/app/src/main/res/values/strings.xml
@@ -5,7 +5,8 @@
     <string name="kolaonline_enhanced">ŠkolaOnLine Enhanced</string>
     <string name="splash_image">splash image</string>
     <string name="background">background</string>
-    <string name="settings">Settings</string>
-    <string name="sign_in">Sign In</string>
-    <string name="refresh">Refresh</string>
+    <string name="settings">Nastavení</string>
+    <string name="sign_in">Přihlásit se</string>
+    <string name="sign_out">Odhlásit se</string>
+    <string name="refresh">Znovu načíst data</string>
 </resources>
\ No newline at end of file
diff --git a/mobile/app/src/main/res/values/themes.xml b/mobile/app/src/main/res/values/themes.xml
index 9e2d1d0..ca4ee9d 100644
--- a/mobile/app/src/main/res/values/themes.xml
+++ b/mobile/app/src/main/res/values/themes.xml
@@ -21,5 +21,7 @@
 
     <style name="Theme.Solen.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />
 
-    <style name="Theme.Solen.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />
+    <style name="Theme.Solen.PopupOverlay" parent="ThemeOverlay.AppCompat.Light">
+        <item name="android:textColor">@color/white</item>
+    </style>
 </resources>
\ No newline at end of file