Most afternoons, Stephanie Buxhoeveden takes a few moments to march back and forth, making at least five U-turns, stand at attention and pinch a digital tomato on her phone.
The unusual ritual is intended to help Buxhoeveden track an unpredictable neurological disorder that largely strikes young women: multiple sclerosis. She’s playing games in an app called Floodlight, which logs her activity and sends it to the servers of drugs giant Roche Holding AG.