I have just started to use a much more detailed app – Sky Safari 3 Pro. Its as easy to use as the others but gives much more detail and lists many more catalogues than just the standard Messier, Caldwell and NGC/IC listings.
It also allows you to save a list of targets for later review.
For example, when I reviewed the DSLR image I took recently of M45 Pleiades, I could see 3 areas of nebulosity corresponding to reflection nebulae. Sky Safari 3 Pro identified these as:
Near Merope: NGC 1435 RN
Near Electra: vdB 20 RN van den Bergh 20
Near Taygeta: Ced 19e RN Cederblad 19e
Id never heard of the van den Burgh or Cederblad lists before!
Tonight was quite cloudy and misty but looking at the star map of Orion, near Orion’s “head”, SS3 Pro identified a Collinder OC, Cr 69, near the star Meissa. This was easy to spot with Canon 10x30IS binoculars. Here is the map: