Prior to Appstark, we were building games and we had to recruit beta testers. We recruited around 800 beta testers for our game on Android, all without a single blog covering us. I will do follow up post about it.
I agree with your point that turn around time for feedback is slower in mobile apps. I think the problem is that in the web its easier for users to communicate with you. The communication channels available for mobile app users are very limited. Appstore is where users are ranting about the apps.
We have built a way for users can directly talk to the developer inside mobile apps. Check it out at http://appstark.com
Testflight does not help you capture the user emotion. It is very important to find out how the user views a certain feedback. Does he view it as a suggestion, question or a problem, it helps to know how big a pain point it is.
We concentrated a lot on the Single player game play and moved the multiplayer aspect to a separate tab called "Challenges". We will work on making it easier.
Our product is similar to them but not the same. We both are trying to develop solutions to the same problem and trying to find the product market fit. Since they are not charging for their service and we are, do you think it would effect our chances of finding product market fit. Do you think we are making it harder for us to find product market fit.