Adding reCaptcha to Android App
Adding reCaptcha to the app to prevent bot registration
2.) (1) Enter a name for your project, (2) Select reCAPTCHA v2 (reCaptcha Android), (4) Enter your app package name, (5) Click "SUBMIT"

3.) (1) copy SITE KEY to value of constant RECAPTCHA_SITE_KEY in you Constants.java config file (2) copy SECRET KEY to value of constant RECAPTCHA_SECRET_KEY in you Constants.java config file

4.) The end ;) Everything will be fine ;)