Verifly gets terrible reviews in the App Store. We have used it twice with mixed results. In July SXM-DFW it approved both of us but AA would only allow one of us to check in online and get a boarding pass. That defeats the purpose. In August CUN-DFW we used it and AA allowed both of us to check in online and get boarding passes. We do not check bags so it kept us out of long check in lines. I would say it was useful then. I think it depends on the airport whether or not it is worthwhile if you are checking bags. I know at DFW there are bag check kiosks where you get and tag your own bags and then give them to an agent. Verifly might be marginally useful in that situation.