I owned a 2nd-generation iPod touch during the “iPhone OS” era. It wasn't always called iOS. I'm not actually sure what it was called on the iPod touch though.

I owned a 2nd-generation iPod touch during the “iPhone OS” era. It wasn't always called iOS. I'm not actually sure what it was called on the iPod touch though. I found some old reference on Apple's site to “iPod touch FW 3”, but I don't remember how much Apple explicitly mentioned it ran iPhone OS.