This happened to me when I first download facer as well. What happened was I selected the wrong smartwatch that I owned. When I opened Facer for the first time, I selected a watch that I thought was cool looking, like the Michael Kors watch...not realizing it was asking what smartwatch I actually owned. To fix this, I tapped the 3 horizontal lines in upper left corner (menu), then I tapped the circle next to my user name, then the gear in top right corner (settings). Under "my watch", make sure you have your smartwatch selected, if not you can change it. Once I had my watch selected, samsung gear S3, everything worked like a charm, and the red sync button went away.