My wife and I got Hum about two months ago. It was easy to set up and worked flawlessly. We both downloaded this app to our iPhones. The app has worked consistently until recently when Verizon updated the app to require mobile device registration. When you log in, it will ask for username and password, and then give you an option to receive a registration code via text or email. I registered my phone with no issues. When we tried to register my wifes phone, however, the initial code was somewhat ambiguous, having two characters that were not discernible between upper cased I (i) or lower cased l (L). After trying a couple of times to get the code to work, I backed completely out and started over. Another code was sent via text, with the same problem as before. After a couple more futile attempts, the service locked her phone out. I called customer support. They didnt initially understand what I was calling to get help with. After some careful explanation, she finally got the idea of what I was calling about. She told me that I would have to wait 24 hours to try again. Other than that, no help was offered. Verizon, get this helpful hint: certain characters, such as lower cased l (L) and upper cased I (i) are not appropriate for registration codes, because they cannot be easily discerned from one another. This is crypto 101, day one stuff. Be prepared for this problem to happen with other customers.