What is it about this app that makes it stand out from all the other apps in the market?

The main reason is that it is designed to be used by the user, and not the other way around. The user is able to choose the network he/she wants to pay for, and then is able to use the service as he/she wishes.

There is also the option to pay with all the networks at the same time, by simply selecting the "All Networks" option.

The user can also choose to pay for the services in a fixed amount of time, or in a fixed amount of money.