TrendSpider's useful S/R Heatmap feature automatically highlights areas of interest in a chart, such as gaps, support, resistance, and consolidation. To turn on this feature, just click the Heatmap button at the top of the screen. Then, you can change the Heatmap preferences by clicking the three vertical lines next to the Heatmap button. There are currently three types to choose from:  horizontal, depth, and trends.