LevelMate

You finally reach the campsite and the caravan still leans to one side. LevelMate reads the motion sensors in your iPhone or Apple Watch and tells you exactly how much to raise each side, so you stop walking back to the spirit level. Pick the setup that matches what you brought along: the Watch at the wheel, a single iPhone on its own, or two iPhones working together. It runs fully offline, with no account, no ads, and no tracking.