iOS stack: Objective C, Swift, ReactiveCocoa, Typhoon, OpenGl, CocoaPods, Cocos2D, CrashLytics Android stack: Java, Gradle. RetroFit, ButterKnife, OpenGl, CrashLytics, NDK, GSON Ruby Stack: PostgreSQL, Ubuntu, ElasticSearch, Redis, Nginx, Passenger, Aws, Heroku Front-end stack: HTML5, CSS3, BootStrap, Pure, ReactJS, BackBone.JS, Ember. JS And more: MongoDB, Azure, PHP5, YII, Node.JS, Mixpanel... + Android Application Development iOS Application Development Android iOS Development Web Development UI/UX Design Microsoft Windows Ubuntu Linux Mac OS X C C++ Assembly Language C# Java Javascript SQL SQLite MySQL MS Visual Studio Eclipse Intellij IDEA Android Studio Svn Git Adobe Photoshop Unit Tests BDD/TDD Google Maps API Google AdMob Google Analytics Google cloud messaging Android SDK Android NDK Facebook SDK Twitter SDK Mixpanel SDK Async HTTP library Retrofit noSQL Xcode Objective-C Ruby on Rails Ruby Bootstrap CSS jQuery REST HTML PHP Mvc Adobe Illustrator Sketch Zeplin Jira Pivotal Tracker Trello Asana Firebase Heroku Redis Bash docker Gulp.Js Grunt.Js React.js Node.js AngualrJS Nginx Apache Agile Amazon Web Services Digital Ocean