Strong knowledge of Android SDK and different versions of Android. UI/UX Design. Firebase for Push notification, Sign-in, Analytics. Google In-app purchase. LinkedIn / Facebook / Google Signup Integration. Paypal, Stripe Payment Gateway. Integrating App with RESTful APIs. Material Design, Widget. SQLite, butterknife, Suger ORM, MPAndroidChart, hellochartsandroid, okhttp, Retrofit, Gson,Volley,I on,OpenGL, facebook login, Fabric , Crashlytics, Google Places. picasso, glide, Android-Universal- Image-Loader Analyze, Code Cleanup, Security fixes.