31. How should different types of Login be used for different types of application?

Anonymous Login

Any application which wants to allow the user to try and then to register if the user is satisfied. Usually Games and E-Commerce. They register users as anonymous and keep everything about the user, statuses, scores, shop cart, etc. and the user can consume the service until he decides to register.

Phone Login

Any application which uses Phone Number as user identifier. Usually Chat Apps, but also can be Games, Banks…

Phone verification   

Any service which collects Phone Number from the users. Even service uses Phone Number as UserID (Chat Apps) or just as additional attribute of user Account (Banks)