I make about $15.00 per month with a free Android app [1], although it has 900,000+ downloads and 500,000+ active installations. Seems I have to rethink my mone

I make about $15.00 per month with a free Android app [1], although it has 900,000+ downloads and 500,000+ active installations. Seems I have to rethink my monetization strategy ;) [1] https://play.google.com/store/apps/details?id=com.marcow.birthdaylist https://play.google.com/store/apps/details?id=com.marcow.bir...