Lesson 28: App Icons, Themes, and Preparing for Release

App Icons, Themes, and Preparing for Release

Your app works. Before publishing it, let's make it look like a finished product rather than a default template.

Setting your app name

<!-- res/values/strings.xml -->
<string name="app_name">Task List</string>

This is what shows under your app icon on the home screen — check it's set to something real, not the default project name.

Generating a real app icon

Right-click res → New → Image Asset. Android Studio's Asset Studio lets you upload a single image and automatically generates every required icon size and shape (including Android's adaptive icon format, which supports different mask shapes across device manufacturers) — you don't need to manually produce a dozen icon sizes yourself.

Setting a proper theme and color scheme

// ui/theme/Color.kt
val Primary = Color(0xFF3DDC84)
val Secondary = Color(0xFF4285F4)

// ui/theme/Theme.kt
@Composable
fun TaskListTheme(content: @Composable () -> Unit) {
    MaterialTheme(
        colorScheme = lightColorScheme(
            primary = Primary,
            secondary = Secondary
        ),
        content = content
    )
}

Wrap your setContent { } content in TaskListTheme { } — this ensures every Material component (buttons, text fields) across your entire app picks up your colors consistently, instead of using Compose's plain defaults.

A pre-release checklist

• Real app name and icon set (not defaults)
• Consistent color theme applied app-wide
• No leftover println() debug statements or hardcoded test data
• Tested on at least one real, physical device — emulators don't always reveal real-device quirks

Next: Lesson 29 — creating a signed release build.