Two feature requests - WebDAV Support and App Manager

[FanboyStudios]

As a Nextcloud user, it would be nice if we could have WebDAV support so we can access and sync files.

Also Amaze File Manager (another nice FOSS app) has an App Manager that can be used to backup app apks and such. This would allow users to keep offline backups in case apps get deleted or uninstall from app stores, devices, etc.