Hi, I'm an Android developer and I would like to create an Astronomy app with a database with all astronomical object (with most useful information and a link to wiki) with a friendly interface. Does anyone know where can I find a free astronomical database? A resource with some typical astronomical algorithms would be nice too.

I got this idea to make an App for Android with the following features:
- Full catalog of NGC and IC objects, planets and double stars
- Realtime conversion from equatorial to horizontal coordinates
- Filtering by subsets of the 2 mentioned catalogs (Messier, Herschel 400, Caldwell, etc)
- Create observing lists
- Observation logs (generating history associated with the objects)

If you have a suggestion with other features, post here!!!
Thanks Shedo!!!