There are two technical charting platforms that really stand out above the crowd.

TrendSpider– TrendSpider is a newer platform that continues to build out the feature-set. It has very clean charts, some cool automated features, and is expanding into data integration.

TradingView – TradingView is a robust platform with just about every indicator one could think of and they are also very receptive to continuously improving the platform. You can do a lot of customization and coding and the feature-set is almost endless.