Hi Georgi,
I congratulate you on your new Android App. I feel the moon calculation must be on Western basis. In Vedic we add the ayanamsa to the western calculation and then the Moon position is calculated. I do hope that you incorporate Moon based upon Vedic Calculation in your App as it would be great help to those following Vedic Astrology.
Thanks & Blessings,
Navneet Khanna
Vedic Astrologer in India