I have had the pebble almost a year specifically for this app and syncing data has been hit or miss. Several updates to the app came out without solving the most important part. Now there is a new firmware for the pebble and new app for swim.com that has a new auto pause feature that made the app worse as now my lengths to get recorded because the thing keeps thinking Im paused mid lap. I can feel my wrist vibrate on and off during the lap as it thinks I am stopped or something. Waste of $100 for the watch.
Edit: still junk
Jarrett Lee about Swim.com: Swim Tracker