How many main() are there in an Android Application?

There is no as such main method in Android Application. In android we can define the entry point by adding intent filter to that activity in Manifest file :

In manifest file we define all Activities we are using in our application. The activity tag which have intent-filter tag (just like below) inside activity tag will work as the main class or Entry class. And this class will execute first when application is opened.

For Example :