How can a small team decide what to test on real iOS and Android devices without maintaining a device lab or a brittle test suite? Use a risk-based matrix: run fast component checks on every change, keep a short set of end-to-end journeys on iOS and Android simulators, and reserve physical-device checks for behaviors that simulators cannot represent. Buy a starter only after checking whether its actual flows fit that matrix.

If you are evaluating an Expo foundation for a fitness product, start with the OTF Fitness Kit , then inspect the live Fitness demo and compare its actual flows with your support matrix.

Start from user risk, not a phone count

A device matrix is a list of combinations you intend to support and the behaviors that matter in each one. It is not a promise to test every screen on every phone.…