I made a tool called Framewatch a while ago that graphs the performance of a project in Game Lab. It's pretty basic but some may find it helpful. Here's the link if you're interested.
Here's what it looks like on a project:
Edit: I found that my tool (ironically) will actually bring down the frame rate because of how Game Lab handles for loops. It's not a big deal on projects running at 30 FPS, but any more and the FPS tends to drop. This is an alternative tool that has almost no impact on performance:
var frameHistory = [];
// Call this at the end of the draw loop
function showFrameRate() {
appendItem(frameHistory, Math.ceil(World.frameRate));
if (frameHistory.length > 60) {removeItem(frameHistory, 0)}
text("FPS: " + average(frameHistory), 0, 15);
}
// Handy no-loop average function
function average(arr) {
return Math.round((arr.reduce(function(a, b) {return a + b}) / arr.length));
}