After an application has been coded, you have to test it. And to test the app you should create APK (.apk) file firstly.
Below is how I do that (for Android application powered by Xamarin):
1. Right-click at your Android project: open ‘Properties’ tab. Be sure that selected drop down is ‘Release’, not ‘Debug’.
*You can define here minimum Android version your app will be compatible with:
2. Click ‘Bild’ -> ‘Clean solution’:
3. Then click ‘Bild’ -> ‘Rebild’.
4. Create the package:
For my solution structure packages are saved to Android/ bin/ Release folder:
5. My APK has been already signed with the private key, so the last step is copy the YOUR_APP_NAME-Signed.apk file to device and install it. That will work for testing now.