Protern Clock for iOS is a cost effective way to generate an audio timecode called LTC.
Pros: Immediately available from the app store; Cost effective
Cons: Does not record run commentary; iPhone will likely need a Lightning to 3.5mm adapter
Dish has a single purpose - generate an LTC time code. It can be left attached to the camera and doesn't require the camera operator to use their phone.
Pros: Turn it on and forget about it; Onboard microphone records run commentary on the right audio channel
Cons: Expensive