MT4 for iOS devices are common for almost all brokers. So you can install the official MT4 on iTunes to start trading.
Please follow the instruction to install FBS MT4:
1. Go to FBS’s official website
2. Go to ‘Trade’ ⇒ ‘Trading Platform’
3. Select MT4 iOS
FBS offers MT4 trading platform for 3 different devices which are:
4. Go to iTunes store and install the app in your device
You need to install the official MT4 trading platform, so the app you install here can be used for any other brokers(which offers service with MT4).
If you are having trouble installing the platform for your devices, please contact to the support team from the Official Website.