Android is an operating system based on the Linux kernel with a user interface based on direct manipulation, designed primarily for touchscreen mobile devices such as smartphones and tablet computers. wikipedia.org

Kotlin is a statically-typed programming language that runs on the Java Virtual Machine and also can be compiled to JavaScript source code. wikipedia.org

Android software development is the process by which new applications are created for the Android operating system. Applications are usually developed in the Java programming language using the Android Software Development Kit, but other development tools are available. wikipedia.org

GitHub is a web-based hosting service for software development projects that use the Git revision control system. GitHub offers both commercial plans and free accounts for open source projects. According to the Git User's Survey in 2009, GitHub is the most popular Git hosting site. wikipedia.org

Is a standard/design guideline.

The Model View ViewModel (MVVM) is an architectural pattern used in software engineering that originated from Microsoft. wikipedia.org

Git is a distributed revision control system with an emphasis on speed. Git was initially designed and developed by Linus Torvalds for Linux kernel development. wikipedia.org

Scrum is an iterative, incremental framework for project management often seen in agile software development, a type of software engineering. wikipedia.org

Agile software development is a group of software development methods based on iterative and incremental development, where requirements and solutions evolve through collaboration between self-organizing, cross-functional teams. wikipedia.org