My Take
I think that this app is simple enough for students to figure out how to use on their own. It's a clean and simple format with easy-to-follow instructions while maintaining a sense of fun as it makes identifying cities into a game. The only issue that I can see in the classroom is when students are stuck on a certain place -- there is no "help" or "hint" option in the game.
How I Use It
I would use this app to teach students about geography; I think it would be a great way to help them learn to associate specific landmarks with their locations (I.e., the Statue of Liberty being in New York City and the Sydney Opera House being in Sydney). It could also help them learn about the different types of architecture in different areas of the world. While testing out the game myself, I found many ways that I was able to identify which city the screen was on -- I looked for souvenir shops, noticeable structures, and more.