In this day and age more and more user data is stored electronically. Users are expecting end-to-end security from every application they are installing on their devices. Application developers too, are seeking to secure all communications between their apps and backends in order to prevents hackers from reverse engineering their protocols and getting access to their databases.
The most basic form of security when transferring data between the application and the service backend is SSL/TLS encryption, and it is very common for developers today to switch their traffic to https and declare their communications as secure. In fact mobile platforms today make it really hard for developers not to use https. That by itself, however, is not enough. Encryption is useless when communicating parties can not validate the identity of their piers.