Yup. My phone usually notifies be of a transaction before a teller even hands back my card.

This actually came in handy about a year ago when my number got stolen. I was sitting at my desk and heard my phone vibrate twice in quick succession. It showed 2 charges at a grocery store in Florida (I am in Chicago). I immediately put a block on my card through Simples app and notified Simple about the fraudulent charges. It made a very scary situation easy to handle.