Before developing, if you're looking to testing applications on your KaiOS device, please make sure that it supports sideloading and debugging. Just don't want you to deal with the hassle of testing through KaiStore's Submission Portal.
Hey rooting people, why are you wandering around here? This place is for developing apps on KaiOS, not destroying the OS itself! Go back to where you belong!
The below portion of the page is deprecated due to being too complicated.
How to enable the Developer menu: The hidden menu can be activated using an app or an ADB shell with root privileges.
Your first app: Basic guide provided by us, BananaHackers.
Device APIs: a wide variety of APIs.
manifest.webapp: application name, version, etc.
Import apps: How to import/install apps