i've been using a lot of apps, so here's a list of them:
•Star Walk and Night Sky = looks like star safari and other apps to point at the sky and recognize a constellation
•Clear Outside = to check the climate situation, with astronomical utilities
•PS Align = you can see the current position of polaris or sigma octants
•SunSurveyor = see the declination and right ascention of the sun for the whole year
•Sunspot = shows the sun position and current name in a little compass
•Scope Tool = shows planets and their moon's positions, current position of polaris and has a angle/compass tool
•ManuaLisa = free manual camera app, you can control exposure, iso, aperture. but nothing more ta=han 1/3 of a second
•Blendeo = blends frames and creates a fake long exposure
•Pics art = the closest that you'll find of photoshop in mobile
•Snapseed = another great editing app
•Lightroom mobile = the best light processing program for mobile
•Google drive = i store all my tiff files and final images there, so you can move between your computer and iphone easily
•The iphone compass = you have a compass, a level, and a latitude/longitude/altitude indicator.
I hope this was useful!
