Does anyone use the Track Attack or Track Addict apps for counting laps and lap times?

We practice at a lake that has a buoy course and I'd like to find a way to count how many laps I do and how fast each lap is. A normal handlebar counter could work but there appear to be some iPhone apps that can do what they do plus some analytics (top speed, etc.)

Just wanted to see if anyone is already doing this and also find out how to best track laps and times.