KaiOS is Firefox OS, a web browser based operating system. It is based on Javascript, HTML5 and CSS languages.
If you want to develop an Opera Mini app for this operating system (I dream about it) the ways are two:
1 - using an app that emulates the Java system, a virtual machine. We are trying to start these 2 solutions:
a)
https://github.com/szatkus/js2me the official Java Emulator of Firefox OS usable on touch screen devices. You can install it from
here, but you cannot use this on your non-touch device. It must be remanifacturized to work on KaiOS. Then everyone could use Opera mini and other Java applications. The Java application univers, everybody know...is very very big. Our devices needs this kind of application. For now is a work in progress;
2 - Opera Mini is a browser. If you have a shortcut to a web emulator like
Browseling everyone can use this solution to navigate with the Opera interface. This solution require less disk space.
I hope this suggestions could help you to develop any solutions.