I rarely use intraday scans though they are a good idea for active traders.I program trade - set my buys and sells before market open and check news and trade activity just before, and at the open to modify my orders. Then I rarely watch the market during the day. If my day orders are not filled at the end of the day, I try again the next day. Mine is a lazy approach.
I have sometimes used the intraday scans and charts offered by Ameritrade. The scans look for gainers with volume increase for instance, which I set for the last hour of trades. The intraday charts, on a minute or 5 minute basis, show graphs of RSI, stochastics, and MA measures during the period set, and are useful for making buy/sell decisions on an intraday basis.