Reboot solved the issue - Created a test app to try collector with our account. Installed the app on my Droid Razr Maxx, was able to log in and open my map. Installed the app on my ASUS TF300 tablet and I get as far as the pop-up that says "Sign In", but I can't get past that, it won't go to the sign in screen like it did on my phone. As a matter of fact the Sign In message just sits there and gives no indication it is registering a click. Anyone have some ideas?