Myelectric multilanguage support

I’d like to add multilanguage support to the really nice myelectric app. I tried it with gettext-files (created them with Poedit) like it is done for example with the user app, but that did not work. I changed myelectric.html to myelectric.php and replaced the strings with php echo prints, but still no luck.

What is the best way to achieve that? How should it be done? In the end I like to do a PR.