Modern Android development hides a lot from us. Between Compose, Jetpack libraries, and modern architecture libraries, it is easy to spend years shipping apps without touching the primitives that make the platform work. I wanted a home screen that actually fit the way I use my phone. So I built my own launcher. It turned out to be the best Android refresher I have had in years. In this session, we will build a launcher step by step and meet the classics on the way: how the system decides which app is "home", how intents and intent filters expose every launchable activity, how PackageManager and LauncherApps list what is installed, how BroadcastReceivers keep you in sync when apps come and go, how AppWidgetHost lets you host widgets, and what really happens in the task stack when you press the Home button. You will leave with a renewed respect for Android's fundamentals, but don't worry, we will also cover much of modern Android development.