Your own private cloud on your own server — files, photos, and sharing synced end-to-end under your control.
Client for self-hosted storage. All traffic goes to your own server; storage and notification permissions are core to sync. No third-party trackers.
The Nextcloud Android app syncs files with a Nextcloud server you (or your organisation) run. Photos can auto-upload from the device, documents open and edit in-app, and shared links work exactly like on the web interface. Everything is stored on infrastructure you control, not on a vendor's cloud. The app handles multi-account, offline files with conflict resolution, E2E-encrypted folders, and integrates with the server's Talk chat, activity feed, and notifications. Uploads are configurable per-folder: Wi-Fi only, charging only, or on a schedule. The client is open source (GPLv2+), as is the server — a complete self-hosted alternative to consumer cloud storage.
Nextcloud by Nextcloud GmbH — Productivity app, 22 MB, requires Android 6.0+. Direct APK download on AppsDone, scanned for malware.