Mobile Application Developer Question:

It could take awhile before your mobile app is earning money (after all, have you seen all the free apps on the App store?). It’ll take time for your app to be recognized and widely used by your target audience. Once that happens, you’ll have the authority to charge a small fee for your app.

A mobile app developer should have some understanding of how to monetize a mobile app. There are several ways: in-app advertising, subscriptions, pay per download.

If your app will be free for the first little while, then your developer should have an understanding of mobile advertising networks.