It depends on the app type, required features, the number of supported platforms, and the chosen development approach. Therefore, it is impossible to get a precise budget estimate without an in-depth analysis of your project requirements.
Here are the approximate range of costs:
the one-platform MVP development costs start at $30,000
a simple cross-platform iOS/Android app development begins at $50,000
a medium complexity native application for iOS and Android will cost you from $80,000
A complex native app for iOS and Android may cost from $110,000.