Why plugin’s JavaScript files are not loaded?
All Dev4Press plugins and addons require jQuery. But, they will work only if the jQuery is loaded with the WordPress proper Enqueue method. If you are replacing jQuery that comes with WordPress with some other version loaded from other location, my plugins will not function properly, and that goes the same for most of the other WordPress plugins that depend on the proper way for loading jQuery.
Can I translate addon to my language?
Yes. POT file is provided as a base for translation in the root folder for each plugin. Translation files should go into languages directory, and WordPress must be set to your language to load the file. The file name for translated and compiled MO file must be the same as POT file with the addition of language code: {addon-name}-{language-code}.mo.
You can check out this for translating plugins using POEdit program:
wp.dev4press.com/tutorials/translating-plugins-or-themes-using-poedit