Backup EnginebackupEngine
Docs/Mobile App/Install on Android

Install the Android App

Sideload the early-access Backup Engine app on Android 10+, sign in with your existing account, and protect your photos, documents, contacts, and calendars.

What the Android App Backs Up

The mobile app protects personal phone data. It is not the desktop agent running on a phone — there are no SQL, Hyper-V, or bare-metal features here. This first release covers four sources:

  • Photos & Videos — your camera roll, uploaded as the original files.
  • Documents — the files you pick with the system document picker (PDF, Office, archives, and so on).
  • Contacts — exported to a standard vCard 3.0 file before upload, read-only.
  • Calendars — exported to a standard iCalendar (.ics) file before upload, read-only.

Data is chunked, compressed, and encrypted with AES-256-GCM on the phone before anything leaves the device — the same on-wire chunk format the desktop agent uses. SMS and call logs are not part of this release; the app requests no permission for them.

Before You Start

  • Android 10 (API 29) or later. Older devices cannot install this build.
  • An existing Backup Engine account — the app signs in to the same account as the desktop agent and the Customer Portal.
  • Roughly 58 MB of download for the APK, plus space for the installed app.

⚠ Warning

This is an early-access build. It is distributed as a direct download (sideload), it is not on Google Play yet, and it does not update itself — see Updating the App below. There is no iOS release yet.

Download and Install the APK

The download URL always points at the current build, so you can bookmark it. Installing on the phone itself is the normal path; adb is there for testing across several devices.

  • On the phone, open the download page (or the direct link) and tap Download APK.
  • Open the downloaded file from the Downloads notification or the Files app.
  • When Android asks, allow the app you downloaded with — your browser or Files — to install unknown apps, then go back to the install prompt.
  • Tap Install, then Open.
  • If Play Protect offers to scan the app, let it. The warning appears because the build did not come from the Play Store.

Why Android Asks to Allow “Install unknown apps”

Android blocks installs that do not come from an app store. Because this build is downloaded directly rather than from Google Play, the OS shows a one-time prompt before it will run the installer. The permission is granted per source app — you are allowing your browser (or Files) to install packages, not granting Backup Engine anything.

  • The prompt links straight to the right screen; you can also reach it at Settings → Apps → Special app access → Install unknown apps.
  • Pick the app you downloaded with and turn on Allow from this source, then return to the install prompt.
  • You can turn the setting back off once Backup Engine is installed — it is only needed at install time.

ℹ Note

The exact wording and menu path vary a little between Android versions and manufacturer skins, but the setting is always per-source and always reversible.

Signing In

  • Open Backup Engine and enter the email and password of your existing account — the same credentials you use on backupengine.com.
  • Complete the brief security check if one appears.
  • The phone registers itself as a device on your account. Settings shows “This device is registered” once that completes.
  • Settings → Sign out signs the app out again; it does not delete anything you have already backed up.

The sign-in screen also has a “New here? Create an account” link if you do not have an account yet, but creating the account on the website first is the simpler path — that is where you choose your plan and data region.

Permissions the App Asks For

Nothing is requested at first launch. The app asks for a permission the first time it actually needs it — when you tap Back up now with that source switched on. Decline one and that source is simply skipped; the rest of the backup still runs.

PermissionWhy it is needed
Photos and videosReads the camera roll so it can be uploaded. On Android 14 and later you can choose “Select photos and videos” instead of full access — the app then backs up exactly the items you allowed.
Contacts (read)Reads contacts to export them as a vCard file. The app never writes or modifies contacts.
Calendar (read)Reads calendar events to export them as an .ics file. Read-only, same as contacts.
DocumentsNo storage permission is requested. The system document picker is the grant — Android gives the app access to exactly the files you select and nothing else.
Network accessUploading encrypted chunks to storage and talking to the Backup Engine API.

ℹ Note

There are no SMS or call-log permissions in this build. They are absent from the app manifest, so the OS could not grant them even if something asked.

Your First Backup

  • On the Home screen, switch on the sources you want under “What to back up”.
  • Tap Back up now. Each enabled source asks for its permission at this point; for Documents, the file picker opens so you can choose which files to protect.
  • The status card tracks progress — current source, chunks uploaded, and how much was deduplicated.
  • Settings → Backup conditions has Wi-Fi only and While charging only. Both are checked before a run starts — if a condition is not met the backup stops right there and tells you why (for example “Wi-Fi-only is on, but you are not on Wi-Fi”). Nothing is queued for later: tap Back up now again once the condition is met.

ℹ Note

Backups in this release are manual: the app has to be open and you tap Back up now. Scheduled background backups are not in this build.

Updating the App

The Android app does not check for updates and will not update itself. Because it is not on Google Play, there is no store update channel either — new builds have to be fetched by hand.

  • Re-download the APK from the same URL; it always serves the current build.
  • Install it over the existing app. Your settings and sign-in survive an in-place update.
  • If Android refuses the update because the signature does not match, uninstall the old app first, then install and sign in again. Uninstalling clears local app state only — data already uploaded is untouched.
  • The desktop agent’s update banner covers the desktop agent only. It says nothing about the phone.

⚠ Warning

The build is signed with test keys for direct install, not with a Play release key. Treat it as early access: install it on a phone you are happy to test with, and keep an eye out for the Play Store release.