KaiOS based on Firefox OS
KaiOS is a mobile Linux distribution for keypad feature phones based on the Firefox OS open-source project. It is developed by KaiOS Technologies (Hong Kong) Limited; a company based in Hong Kong, whose largest shareholder is Chinese electronics conglomerate TCL Corporation. KaiOS runs on feature phones made with low-power hardware and low power consumption (and therefore long battery life). KaiOS supports modern connectivity technologies like 4G LTE E, VoLTE, GPS, and Wi-Fi. KaiOS runs HTML5-based apps. KaiOS supports over-the-air updates and has a dedicated app marketplace called KaiStore. Some applications are preloaded, including Facebook and YouTube. As of 1 April 2020, there are 500+ apps in KaiStore. The mobile operating system is comparatively lightweight on hardware resource usage, and is able to run on devices with just 256 megabytes (MB) of memory.