And also if a server goes down there are still dozens of seeders ready to seed you the files

this would be an ideal use case for IPFS, since that returns the same content address even if you upload something completely independently. I.e. no need for specific torrent files, just upload whatever apps you got and you'll automatically be helping existing uploads.
(with the one caveat that you need to use the same settings, but if everyone uses the defaults that's not a problem)