> I also feel like there's potentially a market for a digital incentive spirometer that could help people do these things. Especially if problems like this are

> I also feel like there's potentially a market for a digital incentive spirometer that could help people do these things. Especially if problems like this are somewhat common. I wonder how accurate an app could get with movement detection if you lie down with your phone on your chest. Probably not very, but might be useful.