As of this morning still "In Review" so keeping my fingers crossed.
After reading more about the Beta testing found it will be limited to devices with iOS 8.0 or higher. This means an iPhone 4 can not be used for beta testing. An iPhone 4S would be OK. This is a limit of TestFlight when beta testing. The app itself needs 7.1 or higher.
Apple uses the app TestFlight to manage beta testing so anyone interested in being a beta tester should go to the App Store and install it to be sure their device is compatible.
You can have up to 1000 beta testers so anyone who is interested can be one. I just need an email address. When I sign you up as a tester you will receive an email invite. Open this on your iOS device using Apple's Mail app not another like Gmail. I have not seen the email yet but I assume if you have not installed TestFlight you will be directed to do so.
If you are interested in being a Beta tester and have devices with iOS 8.0 or higher just send me an email at WattsLeft.email@example.com
and I will add you to the list.
Beta versions are valid for 30 Days and unlike Google test apps you don't need to buy the app to be a tester.
Each tester can install the beta on up to 10 devices. So if you have an iPhone, iTouch and iPad you can test on all three.