I have been using SkySafari for several years now, and it has become the cornerstone of my observing. Even though I have only scratched the surface of its capabilities they are immense. Briefly, it does the following things for you:
1) Replaces the hand controller on your GOTO telescope for wired or wireless control;
2) Replaces your star charts. no more hauling 20 pounds of wood pulp out to field; and
3) Replaces your reference books in the field. Largely replaces them in the office too.
The app is fast and responsive with a beautiful interface. I use it for most of my quick-look questions. Luan is the only other app I use for that purpose now.
Over the years Simulation Curriculum has augmented the basic feature set which bodes well for the future. They have been aggressive on fixing know bugs and database issues. They appear to be reasonably responsive to user requests on new features. For example, list management and generation continues to improve. However, at this point I still find it better to use a full-blown planning application like AstroPlanner Due to the strength of its search and sorts and export the results to SkySafari where I do the final screening.
One area where they remain weak is in the display of dark nebula (principally, the Barnard list). While bright nebula display as the approximate outline of the object, dark nebula display as diamond symbols, with symbol size approximate to the object size. This makes for rather cluttered and confusing display along the plane of the Milky Way, unless you change the settings not to display dark nebula. Lack of shape also makes it rather impossible to confirm the object in the eyepiece, and it is the only remaining reason I would take a paper star chart (Uranometria 2000 in my case) out to the field.