[thristian]

You definitely want the .gba file.

There's no upload-progress indicator, it may just be that the .gba file is taking a while to process - I think Fire Red is like 16MB or something.

[olalonde]

There should definitely be a progress bar in there but it doesn't actually upload the file anywhere, it uses the HTML5 file API which lets you read files locally.

[tekknolagi]

Is there a way to upload saves, so I can do things like automatically have the Legendaries? Yeah, cheating, but whatever :)

[jpfau]

There is an upload savegame button before you load the game. Once you've loaded the game you have to reset before you can load another savegame.

[tekknolagi]

Hmmm. I loaded "FireRed.GBA" then click "RESET" then clicked "Upload Savegame" — and got "FAILED".