The upgrade can be acquired via “Ugrade to ultimate” in the app menu.
The Sky by Redshift is a free app. To disable the ads and get more features upgrade to The Sky Premium for 2.99 USD per year.
Redshift Sky Pro costs a single flat fee of USD 8.99. The upgrade subscription Redshift Sky Ultimate can be acquired for USD 14.99 per year.
As The Sky by Redshift runs independently of Redshift Sky Pro, it is not possible to acquire an upgrade.
The upgrade can be acquired via the shop in the app.
There are three versions of the app. The Sky by Redshift can be used by everybody free of charge. Redshift Sky Pro costs a single flat fee of €8.99. Redshift Sky ultimate is an upgrade, and can be acquired via the store in the app for €13.99.
The apps can be used in English, German, French, Russian, Spanish, Italian, Dutch, Portuguese, Japanese and Chinese.
After the download you can use the apps offline anywhere and anytime. Only updating the orbital data of spacecraft or using the GAIA/USNO data in Redshift Sky Ultimate requires an active internet connection.