You see, My Story: Choose Your Own Path is indeed free to download and play but it has one very, very ugly practice in its. It literally forces you to wait for a very long periods of time to proceed through and eventually finish your story. You will need tickets to get through the game or to even start a specific story.
Additionally, the best choices which are usually the ones that you want to make will be locked behind a diamond barrier. Diamonds are, as I'm pretty sure that you already know, the premium currency of My Story: Choose Your Own Path and the one thing that you will always want to have more of.
While the tickets can be obtained simply by allowing time to pass (don't get me wrong, this can be excruciating), diamonds are only handed out in a very specific moments and as rewards for completing and participating in specific events. Needless to say, diamonds are, as well as tickets, very hard to come by.