Bottom Line: A free matching app with single-play but also a kid-safe, Words-With-Friends type online play feature.
The online part is handled very well, in a way parents can feel safe about. Children choose from funny nicknames (they can't enter their name or even any words in any way), and select their birthday month and year and an avatar. There is no way to chat or communicate in any way with the person they are playing against.
Once the game gets going, the goal is to make the matches the fastest. The full screen of unflipped cards is shown momentarily, so those with a really good, quick memory will do much better than those of us who do not. E beat me two out of three games. Matching certain items provides more points and power-ups. For example, matching rockets increases your card flip-speed and matching lamps provides a quick glimpse of the board.
There are easy and hard modes, which change the number of cards to match on each page.
Mini Mining is very well-done, especially in the online play where there seems to be no lag or other problems whatsoever. It is especially well thought-out and developed and definitely the best matching-game app in the App Store that I have tried. I recommend giving it a go, but...
More than anything else, the quality of the app made me want to download all of the other Airy Labs apps (there are six others) because they're all free and, well, I'm really tired of testing matching games. You can't throw a rock in the educational sections of the App Store without hitting a matching game.
smartappsforkids.com was paid a priority-review fee to complete this review quickly.