Wallaby has come to Google Glass, and while it won't save wearers any money in the short-term, it wants to help them rack up those rewards. What kind of rewards? Credit card rewards. Wallaby tells you what credit card will earn you back the most miles, points, or shopping discounts whenever you spend money. It's been available for Android for quite a while, but now the service has made its way over to Glass, where, since it's practically glued to your face, you're less likely to forget about it.
After installing the Glass app, you just have to say "OK Glass, pay with Wallaby" to have the app show you which card to use at which merchants.
You have to sign up with the service before getting started. You can do that by following the link below, and you might want to snag the Android app on the way, just to be thorough.