Where to go next

Look at what is on your home screen

Three icons that were not there when you started. A dice game with an animation you wrote. A notes app with a real database underneath it. A focus timer with settings, notifications and a chart you drew by hand, pixel by pixel, on a Canvas.

You built all of that on a phone. No laptop was involved at any point.

That is not a small thing, and it is worth sitting with for a second before you read the rest of this page.

What you can actually do now

Not a pep talk — a list. Everything here is something you did, not something you read about.

• Write Kotlin. val and var, types, null safety, collections, data classes, sealed classes, lambdas, extension functions and coroutines.
• Explain what happens when someone taps an icon. The Zygote, the Activity, the lifecycle, the manifest, and what is actually inside an APK.
• Build a screen in Compose — layout, state, recomposition, theming, lists, text input and animation.
• Structure an app that survives. Hoisted state, a ViewModel, a StateFlow, navigation, Room, DataStore and a repository.
• Read an error. This is the one that quietly matters most. You have met around two hundred real error messages in this course and you know that the fix is usually three lines above the scary bit.
• Ship. Icons, empty states, accessibility, dark theme, release builds, signing, and what Google Play really asks for.

Build your own thing next, and make it small

Here is the advice that decides whether people keep going: cut your idea down until it fits on one screen.

Not because your idea is too ambitious. Because a finished one-screen app teaches you more than an abandoned five-screen one, and because the second version is easy once the first exists.

Five ideas, each one buildable with exactly what you already know:

1. A habit tracker. One Room table, one LazyColumn, a tick box per row. This is Pocket Notes chapters 1 to 3 with different words. The whole data model is six lines:

1@Entity
2data class Habit(
3  @PrimaryKey(autoGenerate = true) val id: Int = 0,
4  val name: String,
5  val doneToday: Boolean = false
6)

2. A spending log. An amount, a category, a date. A list, and a total at the top from sumOf. That is Lesson 1.12 and Lesson 4.5 in one small app, and you will actually use it.

3. A flashcard deck. One card at a time, tap to flip. Room holds the cards; Dice Duel chapter 4's animation does the flip.

4. A score pad for a game your family actually plays. Start from your own Dice Duel checkpoint and change the rules to theirs.

5. A "what shall we eat" picker. A list you type in, one button, random(). Buildable in an evening with Part 3 alone, and genuinely useful about twice a week.

The three apps are yours

Every checkpoint ZIP on the Checkpoint downloads page is a complete, working project. They are not read-only examples. Open one, break it, fix it, keep the version you like.

Some first changes that will each teach you something specific:

• Dice Duel — make it best of five instead of first to a target. Add a third player. Keep a history of every roll and show it under the board.
• Pocket Notes — add a tag field to the note. That means a Room migration, which is the single most useful thing in Lesson 4.5 and the one you did not have to do yet.
• Focus Flow — make every fourth break a long one. Add a weekly total to the stats screen. Give focus sessions and breaks different colours in the ring.

Where to look things up

Courses end. Documentation does not.

developer.android.com is the official source, and it is better than its reputation. Three parts of it are worth bookmarking today: the Compose guides, the codelabs (free, step-by-step, genuinely good), and the API reference when you need to know exactly what a function does.

kotlinlang.org is the language's own documentation, and it is unusually readable. The Kotlin Playground there runs code straight in a browser, which is handy on a phone when you want to test one idea without making a whole project.

Jetpack release notes tell you what changed in each library version. Ten minutes there every couple of months keeps you current with almost no effort.

Now in Android is a complete open-source app written by Google as a worked example. Reading real code is the step after finishing a course, and this is a good first one to read.

And the free tool you already have: long-press any Compose function in the Pocket Studio editor and use go to definition. You end up in the actual source of the library. It is startling the first time, and it is how you stop treating libraries as magic.

One honest note about pace

Lesson 0.7 said the enemy was not difficulty, it was burning out. That was true then and it is truer now, because nobody is setting you lessons any more.

Twenty minutes on your own app beats a four-hour session once a month. Every time. The habit is the whole skill.