Firefox OS is a web-based operating system that runs HTML5 apps built for the web. Using things like WebGL, these HTML5 apps can interact with the hardware to allow true native apps outside of a browser along with graphics-intensive things like games. And thanks to the web-based nature of these apps, Firefox OS apps can run on Android devices without a single change in code.
These apps can be installed with the latest version of Firefox for Android, version 29. They behave just like native Android apps in that they appear in the launcher and can be uninstalled through the Settings menu. Their performance is arguable, as web apps have historically been less than optimized, but we’ll have to see.
This is awesome for developers, as they can make the same app work on Firefox OS and Android without changing anything. Not only is it easier, but it actually gives developers incentive to support Firefox OS (which is really important for developing countries, as the latest phone is only $25). What do you think of web apps coming to Android?