Generate SMPTE LTC Timecode from your Android! Free version.

https://www.android-timecode-generator.com

Outputs through your audio/headphone jack to any camera, video recorder, or whatever!
Jam sync your cameras to your Android!

This is the ONLY app on the Android market (right now) that actually generates timecode that your devices can listen to. (Similar to iOS apps MovieSlate and Clockit)

Fully functional free version generates 24fps, 25fps, and 30fps NDF timecode, locked to time of day.

Upgrade to the paid version to unlock user bits, more framerates including 29.97 (NDF or DF) and 23.976, and the option to start timecode at a custom time instead of time of day.
https://play.google.com/store/apps/details?id=com.AaronBernstein.ltctimecodegeneratorpro

Tested with:
Sony EX3
Aja Ki-Pro
Panasonic HPX2100
Panasonic SD93
Panasonic AJ-D450