I would like some modifications to the player. It should allow adding more data to the graph, not limiting to two elements. It should also be smoother/easier to use. The clicking and bouncing boxes kind of get in the way. Instead of boxes over the graph, I would rather update the static area like it does when you click. This might look better if the bottom data were near the graph, either immediately above or below it. Text only for this data would be okay. One example of smooth tracking is the web site for the RunKeeper iPhone app. Here is an example from one of my Couch to 5K workouts. C25K-W5D2 Notice the smooth updates as you drag the mouse over the graph; no clicking required. Only minimal data obscures the graph. Of course, the RK map/graph has other compromises like not showing point detail.
