My kids LOVE DuoLingo — they usually do it on the computer, but there are apps for it as well. It is free. The apps do lack a few of the online features. The only thing I wasn’t crazy about was that I had to establish an account for each person because it tracks your progress individually. And there is a way to chat with other users, so just be mindful of that.
FunSpanish on the iPad. We have the free version; I think the fuill version is around $12-$13. I like some of the game features for my 5yo, but sometimes *I* find it a bit hard to understand.
MindSnacks Spanish on the iPad. I’ve only tried the trial free version. Definitely some topics I have no interest in addressing with my kids (romance??). But there are lots of good topics too. The games are good, but I have trouble with the audio, but I am running it on an iPad2. Best feature: wide range of control over the speed of the audio. LOVE that feature!
More later….