To use Google Maps in an application you need to create a valid Google Maps API key.
The key can be used with any application that calls Google Maps API, and supports unlimited number of users.
To obtain the key one should register to the Google APIs Console providing the application signature key given to application during development and the application package name.
Then, a valid API key must be entered in AndroidManifest.xml file. Later it will be necessary to register application via its
package in this Play Store console together with the SHA- 1 fingerprint of signature key.