Hi,
I am getting around 15-20$ per month with in app purchases and maybe 2$ per month with admob ads.
In app purchases:
september 2016: ~17$
august 2016: ~20$
admob ads:
september 2016: ~2$40
august 2016: ~3$
Feel free to ask me for details or to give me tips to get more users.
App: https://play.google.com/store/apps/details?id=com.levionsoftware.photos