ReSo Backup
Splits a file into shards to keep in separate places; a restore needs only some of them.
About
A backup tool that cuts a file into N Reed-Solomon shards plus a metadata file, any K of which restore it, so the pieces can sit on different cloud drives and a local disk. It can encrypt file contents and names with AES-256-GCM under a password, and works through a GUI drawn with MyGo's native UI, with no web view, or through the rsbackup command line.