tahts interesting,If only it was that smooth for me I had been trying the link on my desktop hence the broken link, it only works if you hit it from your phone. Worked out that I could get it from the app store after reading @andye's post but I can confirm if I hit the link from my phone it does take me to the same app (A1 Rewards).
App asks me for mobile number and password. All I have is an activation code from the SMS. I plug the activation code in as password and give my mobile number and I get "invalid username / password". The forgot password link does nothing.
im on android, and it worked from my laptop,
seems like we are all having problems at differnet stages
edit: if you click on the link from the phone directly, it skips the password bit, and then goes to enter your activation code,
but then I get asked to choose a password and then it dies!