We all know that most of our Summoners are using an iOS device. So here's a guide on how to purchase Gems using iOS.
1. Launch you Brave Frontier app and click the Shop button.
2. Tap Purchase Gems button in Shop.
3. Choose your desired number of gems and click Buy.
4. A dialogue box will appear confirming your gem purchase. Just tap Yes to confirm.
Reminder: Be sure that your iTunes account/Google account is logged in and make sure to fill up all the needed details including your card credentials.