App doesnt work!

We purchased several Restaurant.com certificates to use. We understand the small print and have no complaints on how the certificates can be used. Our problem is that we have certificates to use and the app NEVER works. We constantly get the spinning wheel of patience. It wont log me in, so I cant use the certificates I have purchased. I have used one of six. Very frustrated, as I would have gone through those and purchased more already if the app worked correctly.

JustDontWantToSharw about Restaurant.com, v2.1.9