I've developed a swing trading system for the ThinkOrSwim platform using their built-in scripting language ThinkScript.
The script will mark the entry price, exit price, trade duration and direction as well as P/L per trade and some stats for the duration of the chart. The stats displayed are Equity Gain or Loss, edge per trade, Win/Loss percentage, average Win per trade and average loss per trade.
I'm currently trading this system for a few ETFs, leveraged ETFs and a couple of currencies. The plan is to get implement this as an auto-trading algorithm at some point.