The associate site openjph.org serves as a blog. It currently host the javascript demo of the decoder; the webpage demonstrates that the library can be compiled to javascript, and can run inside a web-browser. Any browser supporting webassembly can be used to view this webpage; examples include Firefox, Chrome, Safari, and Edge, on a desktop, mobile, or tablet.
Another project of interest is the openjphjs project, developed by Chris. You can see there a nice online demonstration of javascript-based HTJ2K encoding/decoding, with a wealth of features and user-selectable options.