I have an android and currently have 2 apps: SkEye and Vortex
Vortex is nice because it has augmented reality and shows pictures of the Messiers. It does struggle at times with orientation and is a pain to get it to tell alt/az coordinates. Also does not seem to have night mode.
SkEye has the nice calibration mode so it can be attached to the scope (not being used at the moment). It also displays alt/az coordinates and field of view. However it does not display pictures of the objects and needs to be manually updated for location. It also seems to not have a huge library.
How much do I gain if I get Stellarium or Sky Safari and which is better? Are there other options to consider? At this point, I do not have a motorized mount and do not plan to use it to directly drive a scope.