diff --git a/app/src/main/java/com/stevesoltys/seedvault/repo/Checker.kt b/app/src/main/java/com/stevesoltys/seedvault/repo/Checker.kt
index ffcdf627..9dbb4c1a 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/repo/Checker.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/repo/Checker.kt
@@ -8,6 +8,7 @@ package com.stevesoltys.seedvault.repo
 import androidx.annotation.WorkerThread
 import com.stevesoltys.seedvault.backend.BackendManager
 import com.stevesoltys.seedvault.crypto.Crypto
+import kotlinx.coroutines.delay
 import org.calyxos.seedvault.core.backends.AppBackupFileType
 import org.calyxos.seedvault.core.backends.TopLevelFolder
 
@@ -36,4 +37,9 @@ internal class Checker(
         return sizeMap.values.sumOf { it.toLong() }
     }
 
+    suspend fun check(percent: Int) {
+        check(percent in 0..100) { "Percent $percent out of bounds." }
+        delay(20_000)
+    }
+
 }
diff --git a/app/src/main/java/com/stevesoltys/seedvault/settings/AppCheckFragment.kt b/app/src/main/java/com/stevesoltys/seedvault/settings/AppCheckFragment.kt
index 076e8a3f..6512b1cd 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/settings/AppCheckFragment.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/settings/AppCheckFragment.kt
@@ -58,7 +58,8 @@ class AppCheckFragment : Fragment() {
         }
 
         v.requireViewById<Button>(R.id.startButton).setOnClickListener {
-
+            viewModel.checkAppBackups(slider.value.toInt())
+            requireActivity().onBackPressedDispatcher.onBackPressed()
         }
         return v
     }
diff --git a/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsViewModel.kt b/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsViewModel.kt
index 2f4fb348..8fc07fbc 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsViewModel.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsViewModel.kt
@@ -45,6 +45,7 @@ import com.stevesoltys.seedvault.ui.MutableLiveEvent
 import com.stevesoltys.seedvault.ui.RequireProvisioningViewModel
 import com.stevesoltys.seedvault.worker.AppBackupWorker
 import com.stevesoltys.seedvault.worker.AppBackupWorker.Companion.UNIQUE_WORK_NAME
+import com.stevesoltys.seedvault.worker.AppCheckerWorker
 import com.stevesoltys.seedvault.worker.BackupRequester.Companion.requestFilesAndAppBackup
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.SharingStarted
@@ -319,6 +320,10 @@ internal class SettingsViewModel(
         }
     }
 
+    fun checkAppBackups(percent: Int) {
+        AppCheckerWorker.scheduleNow(app, percent)
+    }
+
     fun onLogcatUriReceived(uri: Uri?) = viewModelScope.launch(Dispatchers.IO) {
         if (uri == null) {
             onLogcatError()
diff --git a/app/src/main/java/com/stevesoltys/seedvault/ui/notification/BackupNotificationManager.kt b/app/src/main/java/com/stevesoltys/seedvault/ui/notification/BackupNotificationManager.kt
index 868995fd..3cf1230c 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/ui/notification/BackupNotificationManager.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/ui/notification/BackupNotificationManager.kt
@@ -42,6 +42,7 @@ private const val CHANNEL_ID_ERROR = "NotificationError"
 private const val CHANNEL_ID_RESTORE = "NotificationRestore"
 private const val CHANNEL_ID_RESTORE_ERROR = "NotificationRestoreError"
 private const val CHANNEL_ID_PRUNING = "NotificationPruning"
+private const val CHANNEL_ID_CHECKING = "NotificationChecking"
 internal const val NOTIFICATION_ID_OBSERVER = 1
 private const val NOTIFICATION_ID_SUCCESS = 2
 private const val NOTIFICATION_ID_ERROR = 3
@@ -49,7 +50,8 @@ private const val NOTIFICATION_ID_SPACE_ERROR = 4
 internal const val NOTIFICATION_ID_RESTORE = 5
 private const val NOTIFICATION_ID_RESTORE_ERROR = 6
 internal const val NOTIFICATION_ID_PRUNING = 7
-private const val NOTIFICATION_ID_NO_MAIN_KEY_ERROR = 8
+internal const val NOTIFICATION_ID_CHECKING = 8
+private const val NOTIFICATION_ID_NO_MAIN_KEY_ERROR = 9
 
 private val TAG = BackupNotificationManager::class.java.simpleName
 
@@ -62,6 +64,7 @@ internal class BackupNotificationManager(private val context: Context) {
         createNotificationChannel(getRestoreChannel())
         createNotificationChannel(getRestoreErrorChannel())
         createNotificationChannel(getPruningChannel())
+        createNotificationChannel(getCheckingChannel())
     }
 
     private fun getObserverChannel(): NotificationChannel {
@@ -98,6 +101,11 @@ internal class BackupNotificationManager(private val context: Context) {
         return NotificationChannel(CHANNEL_ID_PRUNING, title, IMPORTANCE_LOW)
     }
 
+    private fun getCheckingChannel(): NotificationChannel {
+        val title = context.getString(R.string.notification_checking_channel_title)
+        return NotificationChannel(CHANNEL_ID_CHECKING, title, IMPORTANCE_LOW)
+    }
+
     /**
      * This should get called for each APK we are backing up.
      */
@@ -314,7 +322,7 @@ internal class BackupNotificationManager(private val context: Context) {
     }
 
     fun getPruningNotification(): Notification {
-        return Builder(context, CHANNEL_ID_OBSERVER).apply {
+        return Builder(context, CHANNEL_ID_PRUNING).apply {
             setSmallIcon(R.drawable.ic_auto_delete)
             setContentTitle(context.getString(R.string.notification_pruning_title))
             setOngoing(true)
@@ -324,6 +332,16 @@ internal class BackupNotificationManager(private val context: Context) {
         }.build()
     }
 
+    fun getCheckNotification(): Notification {
+        return Builder(context, CHANNEL_ID_CHECKING).apply {
+            setSmallIcon(R.drawable.ic_cloud_search)
+            setContentTitle(context.getString(R.string.notification_checking_title))
+            setOngoing(true)
+            setShowWhen(false)
+            foregroundServiceBehavior = FOREGROUND_SERVICE_IMMEDIATE
+        }.build()
+    }
+
     @SuppressLint("RestrictedApi")
     fun onNoMainKeyError() {
         val intent = Intent(context, SettingsActivity::class.java)
diff --git a/app/src/main/java/com/stevesoltys/seedvault/worker/AppCheckerWorker.kt b/app/src/main/java/com/stevesoltys/seedvault/worker/AppCheckerWorker.kt
new file mode 100644
index 00000000..cc2e1a0b
--- /dev/null
+++ b/app/src/main/java/com/stevesoltys/seedvault/worker/AppCheckerWorker.kt
@@ -0,0 +1,82 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Calyx Institute
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.stevesoltys.seedvault.worker
+
+import android.content.Context
+import android.content.pm.ServiceInfo.FOREGROUND_SERVICE_TYPE_DATA_SYNC
+import android.util.Log
+import androidx.work.BackoffPolicy.EXPONENTIAL
+import androidx.work.CoroutineWorker
+import androidx.work.Data
+import androidx.work.ExistingWorkPolicy.REPLACE
+import androidx.work.ForegroundInfo
+import androidx.work.OneTimeWorkRequestBuilder
+import androidx.work.OutOfQuotaPolicy.RUN_AS_NON_EXPEDITED_WORK_REQUEST
+import androidx.work.WorkManager
+import androidx.work.WorkerParameters
+import com.stevesoltys.seedvault.repo.Checker
+import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
+import com.stevesoltys.seedvault.ui.notification.NOTIFICATION_ID_CHECKING
+import io.github.oshai.kotlinlogging.KotlinLogging
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
+import java.time.Duration
+
+class AppCheckerWorker(
+    appContext: Context,
+    workerParams: WorkerParameters,
+) : CoroutineWorker(appContext, workerParams), KoinComponent {
+
+    companion object {
+        private val TAG = AppCheckerWorker::class.simpleName
+        private const val PERCENT = "percent"
+        internal const val UNIQUE_WORK_NAME = "com.stevesoltys.seedvault.APP_BACKUP_CHECK"
+
+        fun scheduleNow(context: Context, percent: Int) {
+            check(percent in 0..100) { "Percent $percent out of bounds." }
+            val data = Data.Builder().putInt(PERCENT, percent).build()
+            val workRequest = OneTimeWorkRequestBuilder<AppCheckerWorker>()
+                .setExpedited(RUN_AS_NON_EXPEDITED_WORK_REQUEST)
+                .setBackoffCriteria(EXPONENTIAL, Duration.ofSeconds(10))
+                .setInputData(data)
+                .build()
+            val workManager = WorkManager.getInstance(context)
+            Log.i(TAG, "Asking to check $percent% of app backups now...")
+            workManager.enqueueUniqueWork(UNIQUE_WORK_NAME, REPLACE, workRequest)
+        }
+    }
+
+    private val log = KotlinLogging.logger {}
+    private val checker: Checker by inject()
+    private val nm: BackupNotificationManager by inject()
+
+    override suspend fun doWork(): Result {
+        // TODO don't let backup/restore happen while we check
+        log.info { "Start worker $this ($id)" }
+        try {
+            setForeground(createForegroundInfo())
+        } catch (e: Exception) {
+            log.error(e) { "Error while running setForeground: " }
+        }
+        val percent = inputData.getInt(PERCENT, -1)
+        check(percent in 0..100) { "Percent $percent out of bounds." }
+
+        return try {
+            checker.check(percent)
+            Result.success()
+        } catch (e: Exception) {
+            // TODO maybe show error notification
+            log.error(e) { "Error while checking data: " }
+            Result.retry()
+        }
+    }
+
+    private fun createForegroundInfo() = ForegroundInfo(
+        NOTIFICATION_ID_CHECKING,
+        nm.getCheckNotification(),
+        FOREGROUND_SERVICE_TYPE_DATA_SYNC,
+    )
+}
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 0781f344..8612f614 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -187,6 +187,9 @@
     <string name="notification_pruning_channel_title">Removing old backups notification</string>
     <string name="notification_pruning_title">Removing old backups…</string>
 
+    <string name="notification_checking_channel_title">App backup integrity check</string>
+    <string name="notification_checking_title">Checking app backups…</string>
+
     <!-- App Backup and Restore State -->
 
     <string name="backup_section_system">System data</string>