It may not really be what you want, but I've been developing a mobile-friendly frontend for my K interpreter which makes it essentially a K-based graphing calculator:

http://johnearnest.github.io/ok/mobile.html

The browser security model severely limits potential for doing web scraping with it, but I have found it pleasant to use so far.

Docs can be found here: https://github.com/JohnEarnest/ok#mobile