With Codeshark you can execute functions using small codes, using a command line interface, which also works on touchscreen devices. It can be used for infinite lives, changing levels, adding items, invincibility and everything else you need. And once the tests are finished, just disable Codeshark, without worrying about code changes.
Practical example: The tester needs to increase his life in order not to die in difficult situations. The programmer then creates a function to increase the life, adds Codeshark to the project and links code to the function call created. There, as soon as the code is entered by the tester, the life will be increased. After the test is complete, just deactivate Codeshark so that no player has access to increased life.