KaiOS

KaiOS is a mobile operating system, based on Linux, for keypad feature phones. It is developed by KaiOS Technologies Limited, a company based in Hong Kong, with largest shareholder being Chinese multinational electronics conglomerate TCL Corporation. KaiOS is forked from B2G OS (Boot to Gecko OS), an open source community-driven fork of Firefox OS, which was discontinued by Mozilla in 2016.

List of mobile phones running KaiOS

 * WizPhone WP006 - first KaiOS phone
 * Jio Phone
 * Nokia 8110 4G
 * Jio Phone 2
 * Alcatel Go Flip
 * Nokia 2720 Flip
 * Nokia 800 Tough
 * Jio Phone 3
 * Nokia 6300 4G
 * Nokia 8000 4G
 * MTN 36 Phone
 * Jazz Digit 4G (Pakistan)
 * Orange Sanza 2, Sanza XL
 * Kitochi 4G Smart
 * Vodacom Smart Kitochi (Vida), Vodacom Smart Kitochi (Azumi)
 * QMobile 4G Plus (Pakistan)
 * GeoPhone T15 (Bangladesh)
 * GeoPhone T19 (Bangladesh)
 * GeoPhone T19i (Bangladesh)
 * Sigma mobile X-Style S3500 sKai (Ukraine)
 * Ghia KOX1 (Mexico)
 * Ghia GK3G (Mexico)
 * Advan 2406 'Hape Online' (Indonesia)

List of known versions

 * KaiOS 1.0
 * KaiOS 2.0
 * KaiOS 2.5.0
 * KaiOS 2.5.1
 * KaiOS 2.5.1.1
 * KaiOS 2.5.2
 * KaiOS 2.5.3
 * KaiOS 2.5.3.1
 * KaiOS 2.5.3.2
 * KaiOS 2.5.4
 * KaiOS 3.0