Congratulations on launching! That itself is a huge milestone and sets you apart from a lot of people.
The site looks nice. I didn't have time to create an account to see the inner workings yet. My initial thoughts are: 1) Screen shots of the internals. I.e. if I submit my app, what do I get. I don't want to have to submit it to see if the BetaBoom will be useful to me. 2) I'm not sure that you have a strong enough reason for testers to want to join. I regularly test apps posted here because I know how valuable the feedback is. I don't do it because I want free access to the site/app. It is about being part of the community and helping each other out. 3) Because of #2, I don't know if you will be able to get critical mass to have a usable service 4) Are you planning on making this a business? If so how will you make money?