What is the most useful technical analysis tool to analyze a stock chart?

Answer 1

There is no "most useful" tool in TA. For one person, one tool might be best, and for another person, that same tool might not work well at all. It depends on the person and his/her particular trading strategy. Learn as much as you can and try to find what works with your strategy and with your personality. Many technical traders begin by experimenting with the plethora of fancy indicators that are out there, but eventually come to realize that it's the simple stuff that works best. That and sound money management.

Answer 2

Try ClearStation.com
Also, It has an educational tool.

Good Luck.