All important apps have been rewritten for Android and now I have 46 apps on the Apple App Store (iOS) and 38 apps on the Google Play Store (Android).
Here is my income from Jan 2014 (about $15.5k so far):
In January, I was earning on average $3.5 a day. Since August 20, my daily income haven’t fell below $150 / day. Total income in August is $4,198. This amount is comparable with my salary that I had 2 years ago as a chemistry postdoc at Berkeley.
75% of money are from showing ads and only 25% from sales and in-app-purchases (next week, all my apps can be downloaded for free).
The most profitable are Geography apps, such as:
50 US States (iOS, Android) $2,532 (16.5% of total income).
European Countries (iOS, Android) $2,098 (13.6%).
Flags of the World (iOS, Android) $1,448 (9.5%).
Localization into 9 languages was a very clever decision. United States accounts for 28.4% of total income, Germany 10.9%, Russia 8.8%, France 6.7%, and so on.
The Google Play store is very different from the Apple App store in download trends, search optimization and algorithms. By now, the income from Android apps is just $15.29 but it is constantly growing and I’m just in the beginning of understanding this platform.
Many thanks to everyone who supports me. I will be glad to answer your questions and hear your suggestions how to improve my apps.