The app needs to access the storage so it can save or restore your tracks and settings. Without giving the permission you may not be able to see your tracks history, and you could loose your data.
(All profiles) Recalculate speed from distances, do not use GPS value directly. This may provide more stable speed readings over GPS (Doppler) values. Default is OFF.
(All profiles)Enable invisible quick zoom buttons in the bottom part of the map, improves your orientation