Android is a mobile operating system based on a modified version of the Linux kernel and other open source software, designed primarily for touchscreen mobile devices such as smartphones and tablets.
Gmail is a free, advertising-supported email service offered as part of Google's G Suite, with 15GB of storage, color-coded inbox filters and unsend button.
Hibernate is an object–relational mapping (ORM) tool for the Java programming language. It provides a framework for mapping an object-oriented domain model to a relational database.
J2EE (by Oracle) is a platform-independent, Java-centric environment from Sun for developing, building and deploying Web-based enterprise applications online
YouTube is a video sharing service where users can watch, like, share, comment and upload their own videos. The video service can be accessed on PCs, laptops, tablets and via mobile phones.