This is a sensor data reciever although right now it's alpha and only recieves the online offline status. BUT! There's a new untested featue called the CPU meter. It bases the CPU load of Scratch on the delay of the timer so If scratch begins to lag the CPU data will possibly show it. Remix and try to lag scratch and you'll see what I mean.
I add the LAG CREATOR (don't launch in turbo mode): Step 1 - just variable change. Step 2 - sprites: moving, changing variables, ang uses graphical effects. Step 3 - the strongest step. At the script: step 1, step 2, and all Scratch blocks. All the actions you perform on your own risk. BUT! This loads the processor, but NOT Scratch. Therefore, because of this, you can hang the browser.