I have a web app that you can currently log into with either your email address or your username.
I'm developing a mobile application and I'm just wondering if I should offer the ability to log in with your phone number. If this is the case, a user would first have to provide the service with a number.
I find it convenient on other services I use where I might not remember what email I have connected to it.
Is this a good idea? Would you offer it in a service you were building? I'm trying to decide if its worth the trouble to build.
NOTE: This number would strictly be used for authentication.