Hola! I been developing these two apps for my use but I am glad to share:
Plastic Map shows a map from mbtiles sources for offline use. Maps can be generated using desktop software (ex. Maperitive) and then loaded from the SD card. Markers and configuration are stored in a JSON file.
Here INFO shows calculations derived from your current position and date. Currently only rise and set hours and moon phase, but soon will be adding more calculations and data: celestial bodies positions, eclipses, ephemeris, and practical information.
Please share any thought, idea or issue. My intent with these apps is keep them offline first, with possibly download features and local storage.
-- Juan