I found some hacks that works in Facebook and Google+ via Firefox.
Angry Birds
Bejeweled Blitz
Bubble Island
Bubble Witch Saga
Candy Crush Saga
CityVille
Diamond Dash
Marvel: Avengers Alliance
Monster World
Slotomania
Solitaire Blitz
Zuma Blitz
Google+
Bejeweled Blitz
The main website is: Welcome - leethax.net
If you want to download only the Firefox extension so here is it: leethax.net Firefox extension - leethax.net
Usage:
After installing the extension, restart Firefox and browse to the game’s web page. Depending on the cheat, they will either be activated automatically, or you may need to activate them using the leethax UI. Visit the respective game’s page on this website for detailed instructions (see the list above).
Have a nice day !!!