Looks great to me, although I have not tried it (since it's 100% integration work, devil is in the details). Seems that you've done this before and built the app you would have wanted.
This made me chuckle a lot.
Anyway, this definitely looks like an idea that could take off/has potential. As others have said, it might be better if you did not have to sign up for the 14 day trial with a credit card. However, every trial I've ever signed up for worth paying for later has asked for my credit card information.
And for what it's worth, I understood what it was about without really doing anything.