To herald the upcoming Angel Beats! VN and Charlotte anime, on 22/05/2015 at 23:04 (Japan Time) Visual Art’s/Key released an Angel Beats and Charlotte alarm and news Android app. To my knowledge the app is only available on the Anigema アニゲマ (link is NSFW) Android app store. The installation information page can be found here in Japanese, although helpful screenshots are also included for those who can’t read it. The store page for the Angel Beats and Charlotte alarm and news app is here.
You can also get the .apk file directly from here, password is ‘kazamatsuri’. (I can’t afford a CA signed ssl certificate, so just proceed through the security warning for the site).
After you have downloaded the apk to your Android device, then just install it (you may need to accept app instalations from sources other than the Play Store if you have not done so already) and open the app. The app will download some extra stuff and you are ready to go. Most of the app is pretty self explanatory, so it should not pose any issues for those who can’t read Japanese.
Here are some screenshots of the app:
For those that are interested, Saga Planets (another VN developer owned by Visual Art’s) released a similar app before the release of their latest VN, Hanasaki Work Spring!. The store page for it is here. The direct download link is here (again, password is kazamatsuri).
About アニゲマ:
Owned and operated by Visual Art’s, with apps submitted by many other developers not under the Visual Art’s umbrella, the アニゲマ app store also contains some Key VNs including Tomoyo After, Air, Kud Wafter, and Kanon, as well as Holy Breaker! from H.I design office. Unfortunately the app store is 18+, as it does contain lot of nukige.
(I can’t check since I no longer have a non-japanese account)