I was thinking about a case where I wouldn’t just use a dedicated tuner, and I realized I had a case right in front of me:

My dedicated tuner is downstairs in the studio, and gets regular use in a more “pro” context. But I also keep my nylon string next to my bed upstairs, and like to keep it tuned, as well. This is also where my iPod Touch ends-up every night. So, having an extra tuner on my iPod would be totally handy.