How I Built Icora — A Small Experiment That Turned Into a Lesson on Dynamic Android Icons

🚀 How I Built Icora — A Small Experiment That Turned Into a Lesson on Dynamic Android Icons

Changing the launcher icon dynamically is one of those common questions in the Android community:

“Can I update my app icon at runtime?”

The short answer: Yes — but only if the icons are pre-packaged.
Android doesn’t allow replacing launcher icons with downloaded images, but it does allow switching between multiple predefined icons using activity-alias.

To explore this idea and help developers learn the correct implementation, I built Icora, a lightweight Android demo app that switches app icons instantly using Jetpack Compose + activity aliases.

This blog walks through the full implementation.

🎯 Why Icora Exists

A lot of developers try to replace launcher icons using Bitmaps, downloads, or runtime assets — but Android blocks those approaches.
The proper solution is:

Prepackage multiple icons
Assign each one to an <activity-alias>
Enable only one alias at a time
Disable all others

Icora demonstrates this cleanly with Compose buttons for each icon.

🧩 How Dynamic Icons Actually Work

Android launchers show app icons based on:

android:icon=""
android:roundIcon=""

These must reference resources inside the APK.

Instead of modifying these at runtime, Icora defines many launchable aliases, each with a different icon:

MainActivityAliasA → icon A  
MainActivityAliasB → icon B  
MainActivityAliasC → icon C  
...

All aliases point to the same activity (MainActivity), but only one is enabled at a time.

🗂 Manifest Setup (activity-alias)

Below is the essential part of the manifest:

<activity
    android:name=".MainActivity"
    android:exported="true" />

<activity-alias
    android:name=".MainActivityAliasA"
    android:enabled="true"
    android:exported="true"
    android:icon="@mipmap/ic_launcher_a"
    android:roundIcon="@mipmap/ic_launcher_a_round"
    android:targetActivity=".MainActivity">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity-alias>

<activity-alias
    android:name=".MainActivityAliasB"
    android:enabled="false"
    android:exported="true"
    android:icon="@mipmap/ic_launcher_b"
    android:roundIcon="@mipmap/ic_launcher_b_round"
    android:targetActivity=".MainActivity">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity-alias>

Repeat for C, D, E, F…

🔧 Switching Icons Using PackageManager

The heart of the project is this Kotlin function:

fun setAppIcon(context: Context, aliasClassName: String) {
    val pm = context.packageManager
    val packageName = context.packageName

    val aliases = listOf(
        "$packageName.MainActivityAliasA",
        "$packageName.MainActivityAliasB",
        "$packageName.MainActivityAliasC",
        "$packageName.MainActivityAliasD",
        "$packageName.MainActivityAliasE",
        "$packageName.MainActivityAliasF",
        "$packageName.MainActivityAliasDefault",
    )

    for (alias in aliases) {
        val component = ComponentName(packageName, alias)
        val state = if (alias == "$packageName.$aliasClassName") {
            PackageManager.COMPONENT_ENABLED_STATE_ENABLED
        } else {
            PackageManager.COMPONENT_ENABLED_STATE_DISABLED
        }
        pm.setComponentEnabledSetting(
            component,
            state,
            PackageManager.DONT_KILL_APP
        )
    }
}

This function:

Enables the selected alias
Disables all others
Ensures only one launcher icon is visible

🎨 UI Implementation with Jetpack Compose

Icora uses a very simple Compose UI to trigger icon changes:

OptIn(ExperimentalFoundationApi::class, DelicateCoroutinesApi::class)
@Composable
fun FiveButtonGrid() {
    val buttons = listOf("A", "B", "C", "D", "E","F")
    val context = LocalContext.current

    LazyVerticalGrid(
        columns = GridCells.Fixed(2),
        modifier = Modifier
            .fillMaxSize()
            .padding(16.dp),
        horizontalArrangement = Arrangement.spacedBy(12.dp),
        verticalArrangement = Arrangement.spacedBy(12.dp)
    ) {
        items(buttons.size) { index ->
            Button(
                onClick = {
                    val alias = when(index) {
                        0-> "MainActivityAliasA"
                        1-> "MainActivityAliasB"
                        2-> "MainActivityAliasC"
                        3-> "MainActivityAliasD"
                        4-> "MainActivityAliasE"
                        5-> "MainActivityAliasF"
                        else -> {
                            "MainActivityAliasDefault"
                        }
                    }
                    CustomAppIcon.setAppIcon(context,alias)
                },
                modifier = Modifier
                    .fillMaxWidth()
                    .height(50.dp)
            ) {
                Text(text = buttons[index])
            }
        }
    }
}

Each button enables one alias → instantly switching the icon.

🔄 How Fast Does the Icon Update?

Depending on the launcher:

Pixel Launcher: 1–2 seconds
Samsung One UI: 2–5 seconds
Xiaomi MIUI: may require refreshing home screen

🧪 Common Issues & Fixes

✔️ Multiple icons appearing?

Make sure:

Only one alias has android:enabled="true" initially
The main <activity> does NOT have the LAUNCHER intent-filter

✔️ Icon not updating?

Launcher is caching — wait a moment
Try dragging the app icon on home screen
Some OEM launchers refresh slower

📥 Try Icora or Fork the Project

Feel free to explore, fork, and experiment with Icora.
It’s a great starting point for:

Theming apps
Seasonal icon changes
Premium icon packs
Customizable launcher appearance

🎉 Final Thoughts

Dynamic icon switching on Android is a powerful feature — but often misunderstood. Icora demonstrates the proper, stable, and officially supported way to do it.

If you’re building a customizable Android experience, this technique will open up a lot of possibilities.

📦 Full Source Code

Explore the complete implementation of Icora. https://github.com/ajithvgiri/icora

How I Built Icora — A Small Experiment That Turned Into a Lesson on Dynamic Android Icons