I've been using TouchControl. This is an iPad/iPhone App, no Android. Obviously, there are very few hard buttons compared to Pronto, but one can use the Volume buttons. Screen interactions are much richer and one can be more elaborate with the artwork.

JavaScriipt is the language. Similar to Pronto, it is not mandatory to use JavaScript, but it facilitates slicker interactions with the user. If one looks very closely, one can find bits and pieces of my ProntoScript in my TouchControl programs. IP commands can be directly sent to clients, IR and RS-232 commands must go through a box, such as a Global Caché.

Multi-room is easy -- all you need to do is swap room names, backgrounds, and IP addresses. If you are clever with your design, this could  require only three JavaScript statements per room. It's very powerful to be able to make one change and update the cable box or disc player in all rooms. Also, the modern devices are much faster than Pronto. Interactions that would require too much processing power and bog down Pronto can be done in a blink.

You do need to a different mindset. Don't approach TouchControl as a Pronto on steroids. If you held one of my TouchControl designs next to an ancient Pronto design, you'll see lots of similarities, but they are different under the hood. Some of the cheap tricks in Pronto don't play well in TouchControl and there are some cheap tricks in TouchControl that I would not attempt in Pronto.