I am looking for a free tool which shows buying and selling pressures in trades. I believe this is something that can be shown in a chart. It should already exist on charts but I don't know how to set it. When a trade is done on bid, it is considered as selling pressure and when the trade is done on ask, it is considered as buying pressure. At the end of the day, a ratio can be shown like 45/55 which shows 45% of trades were sells and 55 were buys. I don't care too much about this ratio but I want to see the buying and selling pressure on the chart.
It used to be free but now they only allow it for TD Ameritrade account holders. At least that is my understandings.