It depends on a wide variety of factors, from the type of app and it's features and the developer you choose. The lowest price point hovers around $40,000, while larger apps can cost as much as $125,000. Some estimates for an Uber-like app go up to $300,000. In this guide, we break down the cost of app development to show you where the money goes.
A good tool to estimate an approximate cost for your app idea can be found here.