I want to store files on my server to avoid google cloud and other services.
I’m looking for FOSS software.
I want all the files to be encrypted client side with a masterpassword via an app or a web interface, the server must not have access to them.
An included android app for uploading and downloading would be nice.
I guess what I’m looking for is some kind of FTP server?
If you’re wanting to self-host a cloud service, then Nextcloud is second to none. You can use NextCloud together with Cryptomator for easy client-side encryption, but If you need automatic syncing look into rclone instead.
If you are planning to use this for backups, check out borg backup and vorta(easy to use GUI for borg).