/jp/ - Otaku Culture

Use http://www.manga-watcher.com/ as manga tracker instead of the Play Store offerings. Far superior in every sense.

There's the VNDS android port
https://play.google.com/store/apps/details?id=nl.weeaboo.android.vnds
Haven't tried it, but the dev has a great track record.

If you want to play VN from your phone, the best solution I've found is streaming from PC to decent phone/tablet. https://play.google.com/store/apps/details?id=com.splashtop.remote.pad.v2
Splashtop has been behaving well so far and there's not much lost by going free only.

https://play.google.com/store/apps/details?id=com.wani.talkin2
Obligatory mention. You can just root your phone and modify some files to unlock all of the DLC content. The voice packs are worth it, but not money to be honest.

https://play.google.com/store/apps/details?id=jp.co.winlight.moecurenet
Did a write up on it before http://fuuka.warosu.org/jp/thread/S9991028 and it's really worth a look at the apk but not buying.

https://play.google.com/store/apps/details?id=com.ichi2.anki
https://play.google.com/store/apps/details?id=com.Obenkyo
Do your japanese reps.

https://play.google.com/store/apps/details?id=com.mxtech.videoplayer.ad
If you like watching your anime in Hi10p without transcoding, this is your solution.

https://play.google.com/store/apps/details?id=jp.funsolution.nensho_eng
Have a cute girl cheer you while you do some light exercise.

There's a whole mess of OELVN that don't really deserve to be mentioned, and most of the content you'll find in the market at the moment. I'm sure I'm missing out a lot, like the Madoka games or the cheap clock apps with Live2D tech, but this is a starting point.