QuickMath is an app that is ment to help user practice math in an easy and quick way. You can choose what do you want to work on, and it provide you with equation, then measure your answer time and chceck if your answer was correct. You can track your progress - app is saving users best scores using user defaults.
This app is published on the AppStore: https://apps.apple.com/pl/app/quick-mathematics/id1621110947