After being very disappointed with Track Addict, I switched to an Aim AXL2 dash and Smarty Cam.
My issue with Track Addict was the spotty reception. Even with an auxiliary GPS receiver, sometimes it would work, sometimes it wouldn't. I also didn't like having to mess with my phone every time I went out for a session. My advice is don't bother with phone-based timers.
The Aim dash is loaded with hundreds of tracks, and it begins recording as soon as the bike is started. Likewise with the Smarty Cam. The camera records throttle position and brake pressure, which I've found to be very helpful. The camera has helped me to refine my lines and bike position. When I'm ready, I can start to analyze all of the data it captures. Right now though, the video and data imbedded in the video is enough for me. This is not a cheap system (check Bike Sport Developments). However, I've found it to be a very useful learning tool. I recently had one of the hot local racers take my bike out for a session. The video and data was eye opening! Very, very helpful. IMO, this is a very powerful learning tool.
The AIM Solo 2 lap timer is also very good. It has a lot of the benefits of the dash at a more manageable cost. Check out Moto D Racing.
1998 SS FE #194
2005 749R #362
2006 999 S