Mightier is good, and commercially available. It is tablet based. In original research studies, this was called “RAGE-Control.” Now that it’s more commercially available, it got rebranded as Mightier. Anecdotally beneficial and fun.
Nevermind (www.nevermindgame.com) is pretty cool if you’ve got a mature teen or young adult, but it has an “M” rating from ESRB and so may not be favorable for younger children. It’s well done and entertaining, but requires a decent computer capable of running the game. Specs are on the website.
The Pip (www.thepip.com). It’s tablet based amd for kids of all ages. A lot of kids tend to lose interest after 2-4 weeks, though, because there isn’t a lot of variety in the gaming aspects.
Wild Divine (www.wilddivine.com) is another option. This is more like a “meditation trainer,” though, than a game. Of all the above, it tends to be the least engaging for kids.