diff --git a/PLAN.md b/PLAN.md
index 212dbc4..abd26b2 100644
--- a/PLAN.md
+++ b/PLAN.md
@@ -23,6 +23,7 @@ This is the canonical working plan and progress log for the project. Use this fi
 - Backend analytics coverage now includes a representative key user flow batch.
 - iOS project scaffolding now exists as `mobile/ios-app/HermesApp.xcodeproj` with a shared scheme and XCTest target.
 - iOS sources and tests build and pass in Xcode on an iPhone simulator, and a standalone localization/error-mapping harness passes.
+- Android local unit tests now cover localization, error mapping, and analytics batch conversion, and `./gradlew testDebugUnitTest` passes with the Android SDK installed.
 
 ### Still Open
 
diff --git a/mobile/android-app/app/build.gradle.kts b/mobile/android-app/app/build.gradle.kts
index 33a7296..dcad87a 100644
--- a/mobile/android-app/app/build.gradle.kts
+++ b/mobile/android-app/app/build.gradle.kts
@@ -24,6 +24,10 @@ android {
         buildConfig = true
     }
 
+    testOptions {
+        unitTests.isIncludeAndroidResources = true
+    }
+
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_17
         targetCompatibility = JavaVersion.VERSION_17
@@ -67,4 +71,9 @@ dependencies {
 
     debugImplementation("androidx.compose.ui:ui-tooling")
     debugImplementation("androidx.compose.ui:ui-test-manifest")
+
+    testImplementation(kotlin("test"))
+    testImplementation("androidx.test:core:1.6.1")
+    testImplementation("junit:junit:4.13.2")
+    testImplementation("org.robolectric:robolectric:4.13")
 }
diff --git a/mobile/android-app/app/src/test/java/com/hermes/app/core/analytics/HermesAnalyticsTrackerTest.kt b/mobile/android-app/app/src/test/java/com/hermes/app/core/analytics/HermesAnalyticsTrackerTest.kt
new file mode 100644
index 0000000..9b9c32b
--- /dev/null
+++ b/mobile/android-app/app/src/test/java/com/hermes/app/core/analytics/HermesAnalyticsTrackerTest.kt
@@ -0,0 +1,42 @@
+package com.hermes.app.core.analytics
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+import java.util.UUID
+import kotlinx.datetime.Instant
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+
+@RunWith(RobolectricTestRunner::class)
+@Config(sdk = [34])
+class HermesAnalyticsTrackerTest {
+    @Test
+    fun convertsPendingEventsToBatchRequest() {
+        val tracker = HermesAnalyticsTracker()
+        val event = HermesTrackedEvent(
+            id = UUID.fromString("00000000-0000-0000-0000-000000000001"),
+            name = "screen_viewed",
+            attributes = mapOf("screen_name" to "feed"),
+            timestamp = Instant.fromEpochMilliseconds(1_000),
+        )
+
+        val batch = tracker.toBatchRequest(listOf(event))
+
+        assertEquals(1, batch.events.size)
+        assertEquals("screen_viewed", batch.events.first().eventName)
+        assertEquals("feed", batch.events.first().attributes!!.first().value)
+    }
+
+    @Test
+    fun marksDeliveredEventsAsRemoved() {
+        val tracker = HermesAnalyticsTracker()
+
+        tracker.track("screen_viewed", mapOf("screen_name" to "feed"))
+        val trackedId = tracker.pendingEventsSnapshot().first().id
+        tracker.markDelivered(setOf(trackedId))
+
+        assertTrue(tracker.pendingEventsSnapshot().isEmpty())
+    }
+}
diff --git a/mobile/android-app/app/src/test/java/com/hermes/app/core/errors/HermesErrorMapperTest.kt b/mobile/android-app/app/src/test/java/com/hermes/app/core/errors/HermesErrorMapperTest.kt
new file mode 100644
index 0000000..f9a76e1
--- /dev/null
+++ b/mobile/android-app/app/src/test/java/com/hermes/app/core/errors/HermesErrorMapperTest.kt
@@ -0,0 +1,40 @@
+package com.hermes.app.core.errors
+
+import androidx.test.core.app.ApplicationProvider
+import com.hermes.app.R
+import com.hermes.app.core.localization.HermesLocalizationStore
+import java.io.IOException
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+
+@RunWith(RobolectricTestRunner::class)
+@Config(sdk = [34])
+class HermesErrorMapperTest {
+    private val context = ApplicationProvider.getApplicationContext<android.content.Context>()
+    private val store = HermesLocalizationStore(context)
+
+    @Test
+    fun mapsNetworkErrorsToLocalizedCopy() {
+        assertEquals(
+            "Nätverksfel. Kontrollera anslutningen.",
+            mapUserFacingError(store, "sv", IOException("boom")),
+        )
+    }
+
+    @Test
+    fun mapsGenericErrorsToLocalizedCopy() {
+        assertEquals(
+            "Försök igen.",
+            mapUserFacingError(store, "sv", IllegalStateException("boom")),
+        )
+    }
+
+    @Test
+    fun ignoresCancellation() {
+        assertNull(mapUserFacingError(store, "en", kotlinx.coroutines.CancellationException()))
+    }
+}
diff --git a/mobile/android-app/app/src/test/java/com/hermes/app/core/localization/HermesLocalizationStoreTest.kt b/mobile/android-app/app/src/test/java/com/hermes/app/core/localization/HermesLocalizationStoreTest.kt
new file mode 100644
index 0000000..d5af936
--- /dev/null
+++ b/mobile/android-app/app/src/test/java/com/hermes/app/core/localization/HermesLocalizationStoreTest.kt
@@ -0,0 +1,36 @@
+package com.hermes.app.core.localization
+
+import androidx.test.core.app.ApplicationProvider
+import com.hermes.app.R
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+import org.junit.runner.RunWith
+
+@RunWith(RobolectricTestRunner::class)
+@Config(sdk = [34])
+class HermesLocalizationStoreTest {
+    private val context = ApplicationProvider.getApplicationContext<android.content.Context>()
+    private val store = HermesLocalizationStore(context)
+
+    @Test
+    fun englishStringsLoad() {
+        assertEquals("Settings", store.string("en", R.string.settings_title))
+        assertEquals("Enabled", store.string("en", R.string.settings_enabled))
+    }
+
+    @Test
+    fun swedishStringsLoad() {
+        assertEquals("Inställningar", store.string("sv", R.string.settings_title))
+        assertEquals("Aktiverad", store.string("sv", R.string.settings_enabled))
+    }
+
+    @Test
+    fun unsupportedLocaleFallsBackToEnglish() {
+        store.setLocale("fr")
+
+        assertEquals("en", store.localeCode.value)
+        assertEquals("English", store.localeName("en", "fr"))
+    }
+}