No, the iPhone does not need a cache cleaning app like Clean Master or Battery Doctor. iOS has built-in mechanisms to manage storage and optimize performance, so third-party apps for cleaning caches are unnecessary.

Use a soft, slightly damp, lint-free cloth. Avoid getting moisture in openings. Don't use window cleaners, household cleaners, compressed air, aerosol sprays, solvents, ammonia, or abrasives to clean your iPhone unless following the instructions for disinfecting your iPhone.