There is a VIP version of the game available on in the store that costs only $1. Despite what they tell you in their app page, everything the VIP version of the game is available in the free game. The difference is you don't have to watch a 30 second ad in order to gain those things, you just get them instantly when you hit the button. I feel it is well worth the $1 price tag as those ads are quite tiresome after watching the same ones over and over!
For your convenience, I'll list what it says on their app page:
- 10% Additional medal reward when returningInstead of the option to watch an add or continue without the 10% bonus, you just have a button to continue with the 10% bonus.
- 20 free crystals from time to time during the gameI just recently found out that this is also in the free version, you just need to play an ad to gain them just like in Endless Frontier.
- A large amount of gold gifts every 10 minutes
- Every 20 minutes, 2 times the attack power and 2 times the battle speed
- Data sharing: Free versionThis means that you can play both of the versions with the same save.