Guys, I ran into this issue as well. To my horror I discovered my trusted browser (Chrome) refuses to display http content over https (which this plugin tries to do: access the font APIs over http). Firefox for me displays the fonts as expected.
I went ahead and changed the plugin code in my installation to use https for both fonts.com (fonts-com.php) and google web fonts (google-web-fonts.php) and that seems to have temporarily fixed the issue for me. If this is your situation too, I’d suggest you try the same.
