ThinkOrSwim aka TOS (
https://www.thinkorswim.com) a trading platform used by some members of this site.
ThinkOrSwim is an American brokerage offering live and online investor education services.
In addition, through its brokerage subsidiary, Thinkorswim, Inc., Investools provides services to about 100,000 funded trading accounts for self-directed option traders and institutional users who invest in equities, exchange-traded funds, futures, mutual funds and bonds.
Source:
https://en.wikipedia.org/wiki/Thinkorswim
Software product comparison:
https://en.wikipedia.org/wiki/Technical_analysis_software
