Love the idea of Keet, but up to now I've been disappointed.
Firstly, it's been about-to-be-open-source for what feels like years now.
Secondly, I've not found it reliable - post a larger file, a couple of hours later it won't download, or stay downloaded (it previously was there, but now it's waiting for other peers to be back online before I can access it again).
But the worst thing is, every time I come to use it after a week or two, I can't do anything without a forced upgrade. And I've lost access to using it at all on a few older devices (particularly on iOS) - it forced an upgrade, then never worked again. As a relatively non-technical person, this makes it is hard to trust. (How do I know it is a genuine upgrade? If a bad actor was involved, how do I know I'm not just replacing it with a compromised version? ...or at very least, I can't be sure it'll still work after I upgrade, which means I can't rely on it for anything longer term than just whatever I'm using it for today).
This also means introducing it to other people is problematic - it solves a bunch of communication, privacy and file transfer problems beautifully, but if their experience is usually 'it doesn't work', then it's pretty much a non starter in that context.
I very much hope that my trust in it can be rebuilt, and the technical wrinkles can be ironed out, because it has masses of potential.