This project demonstrates the usage of reCAPTCHA Android library and how the captcha token is verified with the server. To use this project you will need a site key and a secret key. You can create one for your project here : https://www.google.com/recaptcha/admin#androidsignup

Android API Usage : https://developer.android.com/training/safetynet/recaptcha.html
More about reCAPTCHA at Google Developers Blog : https://android-developers.googleblog.com/2017/06/making-internet-safer-and-faster.html
More about token verification : https://developers.google.com/recaptcha/docs/verify

This App uses Lottie Animation library (everyone loves animation right ?) which brings some fancy stuff to App :P
More about Lottie for Android : https://github.com/airbnb/lottie-android
The animation files are downloaded from : https://www.lottiefiles.com

Lottie view has smooth Spring animation thanks to Rebound library by Facebook. Tap on Lottie view and it will animate on tap and release action (i.e. MotionEvent.ACTION_DOWN and MotionEvent.ACTION_UP event). More about Rebound library : http://facebook.github.io/rebound/

To show any alert or message App uses Alerter which is quite cool, have a look here : https://github.com/Tapadoo/Alerter