This app (Free - no IAP) is a collection of useful tools for astronomers. It is intended to be used far away from civilization, so all the info can be accessed locally.
Ranked in these QuestionsQuestion Ranking
Pro Shareable data
The information gathered using this app can easily be emailed or sent in HTML format to similar apps.
Pro Observation log
Night Sky Tools includes an observation log to save calculations or equipment settings for future use.
Pro Requires no internet connection
Since most stargazing takes place away from WiFi, Night Sky Tools doesn't require a connection in order to get important information.
Pro Night mode for faster eye recovery
In night mode, the screen turns red in order to minimize the time that it takes for eyes to see again in darkness.
Con Not completely self-contained
While one of the main features of this app is functionality away from internet connection, not all data can be accessed. More specifically, things like asteroids and satellites that must be updated often cannot be viewed without an internet connection.