The Android OS allows you to set default application for just about everything. It is useful, for example, if you want to make your Chrome or Firefox browser as default browser instead of your stock browser, or if you’re tired of the email app you installed and you want to try another, you can do it without removing the first app by changing the “use as default” settings.
How to set or change default apps in Android?
Go to Settings – Applications – Manage Applications. Scroll through the list of applications and select the app you wish to deselect as the default.
In the Application Info section that opens, scroll down and tap the “Clear Defaults” button.
Now, next time you use another app, or perform an action that requires an app to open where no default is set, Android will ask if you wish to use the app as the default.
Just enable the option “Use by default for this action”. That’s it!