Question about an android terminal command.

Hello I am here (sorry if this is the wrong place for this type of question) hoping if any of you guys have heard of a android terminal emulator command that slows ui, or the device in general. I am trying to crack an app called nvidia shield hub it has some tabs that disappear less than a second after opening app for the first time. (remnence of nvidia hiding the stream service and grid games *which DOES WORK with non tegra devices.*) yes i tryed it and got to the hidden tabs on 2 devices my nexus 7 2013 and Samsung tab 3 7.0. I had a friend show me one that slowed ui by generating something to keep the GPU or CPU busy. but I lost contact with them.
Any ideas or info will help ty.

Sorry for my bad English and grammar English is my second language.