My kids love the DragonBox apps, but do not see any connection with actual algebra/geometry at all. My favorite math game app is Wuzzit Trouble, which works addition/multiples in a puzzle environment.
Playful Minds: Math is a curriculum app, like Dreambox. It is not adaptive, but has a fixed sequence of tasks. Kids earn tokens and spend them on dressing their avatars. It's less flexible than Dreambox, but it's also much less expensive and doesn't require a subscription, and it doesn't overstress the basic concepts. DD loved it the summer she was 5; she worked almost all the way through it on an international trip.
DD8 found Dreambox useful and entertaining when she was in K and working at a 1st/2nd grade level. Now she is trying to bring her account up to date with her current working level; she is partway through the 3rd grade curriculum. It's worth the free trial to see if your kid likes it.
Pros: Its virtual manipulatives and overall curriculum were good for place value and doublings. She liked the cutesy playground feel to it, which drove me nuts, but whatever. Now she works on it because it's a school account, so she can use it to prove to her teacher that she is actually ahead.
Cons: It's somewhat repetitive and slow. It teaches related concepts in a similar way, but doesn't let kids whiz through more quickly on the second or third very closely related topic. If you get bored and quit before the exercise is over, it loses your whole progress for the task and you have to start over next time (tasks should take around 5 minutes each). Twice, now, the environment has changed on us in ways that DD doesn't like, and the company has not been particularly responsive about why. It's set up to teach the deep concepts behind basic math like addition or place value, but doesn't have a problem solving component to stretch the kids who already get number concepts. If we were homeschooling I would find it to be an incomplete curriculum in that way.
