Founded and created by Grand Cane Master Robaina, American Cane Self Defense is a complete, tactical martial art that includes empty hand translations. As a self defense tool the cane is a powerful self defense tool with substantial leverage that is also completely legal. You can take your cane on a plan, a train and across state lines without the need for a special permit of any kind.
Your review is very general. If you're referring to prices of the canes or the cane self defense training that has nothing to do with the app itself. Would be glad to reply to anything specific you have to contribute, else it's impossible to take any corrective action based on what you've written.