I think I've tried them all (on Android, so it excludes Auto Pilot... which I hear is great). Personally I'd say it's hard to beat DJI's Pilot app for all around use. I'd have to say that I trust it the most mainly because of its built in warnings. Litchi is _very_ solid as well and adds a _ton_ more features. If I had to choose one aftermarket app I'd probably choose Litchi. However, I'd say that I now use Vertical Studio more then Litchi as VS's visual tracking works great. I just could not get a lot of shots without it.
But those are my top three choices (Android) for all around flying.
There are other apps, such As HiveMapper that are great apps but they are not as well rounded.