There seems to be a key element of trust required for using this site. How do we know the code cycret.com runs is the same as what's on Github? i.e. How do we know cycret isn't actually running different code that serves as a man-in-the-middle by creating RSA encrypted channels to both the sender and receiver, but archiving plain-text of all their communications as they pass through cycret.com? Programs like GPG can be compiled from source on your own computer so that, if you understand the code, you can trust it. This doesn't appear to have that advantage!
I don't know that much about web stuff, so if there is an easy and trustable way to see what code cycret is actually running without taking your word for it, I'd be very curious to know how!