I have a requirement to allow the user to login to the app from just one device. So basically there are apps which first asks you to register via sms from the device and only then allows you to use the app from that device.
If we try accessing the app from someone else’s phone (device2) and the user creds that was entered in device 1 it would not allow us to login.
If the user wants to login from some other device(device 3 or device 2) he will have to first register into the new device via sms after which he would not be allowed to login from device 1.
Source: Android Questions