I have been making decent money with my android apps monthly. I also been using other techniques as trading online which I learn from Faq Forex to make some money without that much effort.
And if you run a business then I recommend for you service cloud to support your customers: https://www.salesforce.com/eu/products/service-cloud/overview/
StartApp is currently best advertising agency in android.
Moreover the ConsolidationNow of thier SDK in our Apps is very easy and takes only 3 steps.
They pay upto 55$ for 1000 US installs.