Sometimes it helps to close and re-open the app to reset things. This is called "killing the app" - but it's very easy (and not at all dangerous)!
- Double click on the round home button on your iPhone
- Navigate to the GOFAR app and swipe it up.
After doing this you will typically want to reopen GOFAR.
If you want you can see a short video on closing apps on an iPhone 6 (running iOS10)
The home button on an iPhone is the round one at the bottom of the phone screen.