Convert a Open source Java application to a standalone application utilising HTML5, CSS, javascript & sqlite

Nyagua is a software that helps to manage your home aquariums. Here is the source. https://nyagua.sourceforge.net/.

I am looking for quote to convert this application to run on any platform (windows, Mac OS & Linux) as a stand alone application.

Functionality needs to be identical, and fully tested.

Please review the application from the link above and let know your estimate & time scale to complete