My Take
I highly recommend this app to teach physics principles. I would say that you would probably need to look the app over and then you can ask the students to find examples of certain principles, for example, kinetic or potential energy, or certain types of collisions. If there isn't some structure, then it can just end up being lots and lots of playing.
How I Use It
I use this app in teaching my students stability and motion. It is a super fun and addicting way to allow students to safely build and test creations in a virtual physical environment. Students observe how things react in collisions and with gravity. The students always want to play this app. It is great for introducing and showing examples of physics principles. It is also great for early finishers.