If you have a Tentacle Sync E and want to use the professional Movie Slate App for iOS, you'll need to consider a few things. If you don't have it yet, you will need of course the latest Movie Slate Pro Features 8.9.5 to use any kind of external timecode synchronization.
- Make sure your Tentacle is running in Green Mode
- Open the App and tab on the timecode > Sync > Connect to Tentacle
The App usually chooses the first Tentacle on your list no matter if its in Green Mode and outputting timecode or if its in Red Mode. So make sure that the Tentacle that is selected by the App is actually in Green Mode.