R.I.V.K.A. is a bot available on a variety of mobile platforms, which include iPhone and Android based mobile devices. The program has a 2,5 star rating on the AppStore. The experience of chatting with R.I.V.K.A. is a bit static at first (you have to take the initiative), but after some time the bot starts asking questions by herself too. Funny experience was when she started to give hints about a certain handsome Computer Programmer, couldn't figure out who she meant though.
The program requires a working internet connection, so it seems the answers are requested from a remote server.