My members on my RC3 forum have liked the addition of the App. I haven't upgraded to RC4 because I'm waiting for some mods that I use to get updated first.
But, I updated this last night to another test forum that is running RC4. I used the package that they have on their site because I learned in the past that the mod gets updated and released there first. I had no problem installing the mod and publishing it on their site. There are easy step by step instructions there that make it pretty much fool-proof.
Also, I don't like having to register at every single place for something I'm going to use one time, but I think of it as the cost of something that is free. If I can't register and take a little bit of effort out of my own day for something that I'm not getting charged for... well, I won't pass judgment on that behavior. It's nothing to do in return for getting something as useful as the App. (Also, I've found that when I had questions in the past, they were answered just as quick, if not quicker, than on the SMF site for support, so it was worth the time to register.)
As far as price goes, Apps are freaking cheap. It's less than a coffee/mocha/cappuccino. As far as the comment about it not fitting in with the Free-ness of SMF, you still use hosting, your domain name, your computer, your electricity to run the computer, etc etc etc and it didn't keep you from using SMF.
