Some ideas for your synopsis

• Wireframes / UI design with MockFlow, Figma, or similar tools
• Firebase Kotlin Extensions
• Microsoft Power Apps
  Apps with less or no code!?
• Proguard: Obfuscation, Shrinking and Optimization
• Android View Binding
• Android Things, IoT
• Bluetooth in mobile applications
• MPAndroidChart chart library
• Android Jetpack
• MobilePay in Android applications https://www.mobilepay.dk/da-dk/Developer/Pages/integration.aspx
• Android wearable (Android API 20W)
• Architectures of Android applications: MPC, MVVM, MVC etc.
• Kotlin compared to Java (much more that we did in class)
  An interesting book: Peter Spath: Learn Kotlin for Android Development, Apres. Availabe from bibliotek.dk. Thisbook is mainly about the Kotlin language (very little on Android development)
• Android (the latest versions), new features
• Google TV
• Google Flutter https://flutter.io/flutter-for-android/, https://github.com/flutter/flutter (scroll down)
• How to make apps for iPhone / comparing iPhone development to Android development
• How to make apps for Windows 10 compared to Android http://www.microsoft.com/windowsphone/da-dk/default.aspx
• Cross-platform apps
• Java for iOS, Windows, etc. http://www.codenameone.com/
• Android security
• Adapting Android apps to different screen sizes and screen densities.
• Android game programming
• Android audio, video and camera
• Android styles and themes
• Android NFC (Near Field Communication) (communication with very nearby devices)
• Internationalizing and localizing your Android application to support different languages and cultures.
• Dependency injectors for Android, like Dagger http://square.github.io/dagger/
• The development enviroment "MIT App Inventor" http://appinventor.mit.edu/explore/
• Android Broadcast intents and Broadcast receivers
• Designing and programming Android apps to run in desktoop browsers http://www.theverge.com/2015/4/3/8339197/android-apps-on-windows-mac-linux-chrome-os
• Google Firebase vs Visual Studio Mobile Center
•  Telerik UI for Xamarin
• and many other ideas ...