Thanks to support from NGI Zero open source funding (npub1dk0…k0wd) and CalyxOS (npub1xwa…75q9), I was able to improve Seedvault's app backup. Taking inspiration from The restic backup program (npub18j3…w0c9) and BorgBackup (npub1aey…y08m) 2, backups now use de-duplication, compression and chunking - resulting in smaller and faster backups. Snapshots allow you to restore previous states of your device. Available on free Androids soon.
Docs: https://github.com/grote/seedvault/blob/app-dedup-research/doc/README.md#seedvault-app-backup-repository-documentation
PR: https://github.com/seedvault-app/seedvault/pull/750