Maximize Flash Bookmarket. Make any site's flash app or game full-screen by adding this to your bookmark bar.
Go to the install page and drag the link to you bookmark bar.
Then when on a site with a flash app or game, click the button in the bookmark bar. If it finds the Flash player, it will enlarge it to fill the screen. Refresh the webpage to undo.
Sometimes, it will even find the ".swf" source of the flash app. In that case, an icon will appear at the top center for a few seconds allowing you to download or directly bookmark the full-screen version.
I made this because my kids enjoy playing Flash-based educational games online, except they squint and lean forward to look at the small game that's using 20% of the available screen.