Astronomy Observer app is an app that help astronomical observers to arrange their observation plans reasonably.
    Thanks to the improvement of the computing power of mobile phones and the application of new technologies (AR), it is possible to calculate the position of celestial bodies and the celestial ephemeris on the mobile phone, and AR can display the positions of celestial bodies. 
The Astronomy Observer not only calculates the daily sun-moon position, planets rise and set, constellations, important stars, and messier objects which can be seen . In addition, various types of celestial bodies and important star catalogs are also collected, and the position, rise and set of each celestial body are calculated, and finally the ephemeris of the celestial body is calculated for one year. AR shows the constellation division, constellation position, star position, important star display, solar system celestial position.
    
 
The App is divided into the following parts
1. Daily: Daily twilight, moonrise and moonset, planets, and constellations, stars, messier
2. Browse: Browse constellations, stars, solar systems (sun, moon, planet, comet), deep sky objects (messier, galaxy, star clusters, nebulae), important star catalogs (HR, HD, HIP, SAO, CCDM, GCVS, TYChO, NGC)
3. Event: Calendar of astronomical phenomen
4. AR: AR shows the position of celestial bodies
5. Mine:

【Astronomy Observer Membership】
View all the celestial bodies catalog, One year ephemeris for all celestial bodies can be viewed, View AR images of any time,no ads
Purchase rules:
[Monthly Membership] Purchase a monthly member for $ 0.99 / month and renew it automatically every month.
[Annual Membership] 4.99 $ / year to purchase annual annual membership and automatically renew it annually.
[Lifetime Membership] $ 14.99, only need to purchase once, valid for life

[Prices in different countries or regions should be converted according to the US dollar exchange rate]

Purchase Notes:
1. The account will be automatically renewed and deducted the corresponding fee 1 day before the expiration.
2. If you need to cancel the renewal, please cancel in your personal iTunes account at least 1 day in advance.
3. After purchase, users can manage or turn off automatic renewal in personal account settings.

Terms of Services : http://www.astronomyobserver.net/h5/astronomy/user/en
Privacy policy: http://www.astronomyobserver.net/h5/astronomy/privacy/en