Hello, I am new to this app as I was looking to be able to track my pain. I am glad I found this app it's a great idea. . I recently received a spinal cord stimulator for my Chronic back pain. It's been a blessing a God send. The unit is Implanted under the skin and you control the stimulation with an iPod. It basically works by blocking the nerve signals to the brain, so you don't feel the pain. Anyone who suffers from chronic pain of any sort should look into this procedure.