If you’re talking about the FOSS app, it’s just a nice UI for your RealDebrid web-interface. It can:
tell you how many days you have in your RD subscription & your RD points
list the RD+ streams you’ve clicked on/watched so far
stream your RD files, share em, download, all that.
download from link/magnet using RD servers
search through popular indexers (which RD can’t do, but Torrentio does it) and optionally add them to you RD library
But as far as I can tell, it’s nothing you can’t already do with the RealDebrid webpage & the stremio interface with Torrentio. Unchained looks nice though.