Incremental folder backup · Android
FolderVault quietly mirrors the folders you choose to Google Drive, one new file at a time. Turn on encryption and the cloud sees only sealed bytes.
● It only ever adds to the cloud. It never deletes your backup.
The idea
Photo libraries, scans, document archives, exports. You pick a folder once; every new file inside it lands in the cloud on a schedule you set. Define as many backups as you like — each maps one local folder to its own cloud destination, with its own schedule, encryption, and settings.
Mirror your camera roll to one place and your scanned documents to another. They run and are managed completely separately.
Choose a folder, choose a schedule. New files upload automatically in the background — even after a reboot.
Unchanged files are never re-sent. The first sync of a big library spreads over several runs; after that, runs are quick.
Deleting a file on your phone does nothing to the cloud copy. The archive only ever grows — your backup can't be wiped from this app.
Turn on encryption and files are sealed on your device before they leave. Google Drive stores ciphertext it cannot read.
Because it runs unattended, FolderVault keeps a clear log and notifies you if a backup quietly stops working.
How incremental backup works
FolderVault keeps a local record of everything it has already uploaded. On every run it walks your folder and decides, file by file, what to do.
It recurses through your chosen folder and all its subfolders, recreating the same folder structure on the cloud side so your archive mirrors what you see on your phone.
A file counts as new or changed if its modification date or its size differs from what was last uploaded. Unchanged files are skipped entirely — they're never re-sent. Detection is by date and size, not by reading file contents.
With encryption on, the file is encrypted on your device into a .crypt copy as it uploads. Nothing is held in memory wholesale, so even very large files stream through safely.
Files go up one at a time, start to finish. A completed file is permanent progress — if the system stops the job, the next run simply picks up where it left off. Small files first, very large files last, so one giant file never holds up the rest.
Each upload is logged so the next run knows to skip it. When a file changes, the new version is uploaded as a separate timestamped copy — the old one stays put. You can set a retention rule if you'd rather keep only the most recent versions.
Encryption
Encryption protects what's inside your files. File and folder names stay as they are (with a .crypt added), so your archive is still navigable in Drive — an intentional trade-off.
.crypt file carries everything needed to decrypt it (except your password), so restore works on any device, even after a reinstall.What Google Drive stores when encryption is on: an opaque container of bytes. The plaintext only ever exists on your device.
Honest limitations
A backup tool you can trust is one that's upfront. Here's where FolderVault is the wrong fit — and what to expect.
Files go up; they don't come back down automatically. To recover, you download the folder from Google Drive's own app, then — if it was encrypted — decrypt it here.
A changed file is saved as a new timestamped copy, so something edited every day piles up many versions. It's built for archives that rarely change. A retention rule can trim old versions.
It doesn't read file contents to detect edits. A tool that rewrites a file without changing its size or modification date won't be noticed as changed.
The list of what's already backed up lives on your device. Clear the app's data or reinstall and the next run uploads everything again. Your existing data on Drive stays safe and untouched.
Getting your files back
Use Google's own Drive app to download your backup folder to your phone. FolderVault leaves the heavy cloud work to the tool built for it.
Open FolderVault → Restore, pick the downloaded folder and an empty output folder, enter your password. Every .crypt file is decrypted locally, rebuilding your original folder tree.
Decryption happens entirely on your device. The password plus the salt stored inside each file is all it takes — so restore works on a brand-new phone, with no account and no internet connection.
password + file header → your files
If a backup was not encrypted, there's nothing to decrypt — the files you downloaded from Drive are already the originals.