Audiotools is not free on iOS and rew are for those who are advance users. If your new to rew it can be overwhelming and need watch YouTube to get to familiar on how to use it. Majority of us users want quick point and measure kind of thing.If you are serious about room correction and measurement, you will soon discover there are way better techniques than a making a singles sweep with mic in one position. You dont even need to buy HouseCurve (one alternative on Android is AdioTools) - REW is free software on Windows and Mac.