According to the website MineMum, a sandbox game is one where players create a game themselves by manipulating the world within it.
National Geographic’s Puzzle Explorer is a new app where players can create mazes in different geographic settings. You can download it here. My daughter and I created mazes and played on already built mazes in the Yucatan Peninsula and Antarctica. I will warn you that this is addictive. In Antarctica, the goal is to collect three cameras located in different places in the maze. You travel across ice blocks (see below). The tricky part is not all of the maze is connected. Players have to manipulate blocks of ice and giant snowballs to create new pieces of the maze that can be crossed. Each camera contains informational text with a photograph background. When you have collected the cameras, you win the game.
Using this app was a lot of fun! You have to really think to develop a strategy to meet your goal. I like the combination of informational text and game-playing. Mazes can be shared between players which brings a social aspect to the game. Try out the free version and if you like it, you can complete your app for $2.99 with settings for the Himalayas, the Nile River Valley, and the Australian Outback. If your child/student is going to have screen time, give them something that will make them think and create. As they are creating, players will be learning facts about each of these places in the world. This makes the app a way to introduce these geographic locations. Speaking of geography, you could also use this app to talk about land forms. I think this app would be good for ages 6-12.