My Take
This is a great way for students to practice the logic and critical thinking skills involved in solving tangram puzzles without the storage issue of where to keep the different levels of puzzles and the issue of tracking progress and understanding. The pieces are durable and easily manipulated, especially compared to manipulating shapes right on the iPad screen. The fact that are no words to read makes it useful for even the youngest students as well as ELL. Directions are clear and it's easy to choose and differentiate between levels of difficulty.
How I Use It
My students use Tangram for Osmo in centers. They play in groups of 2-3 for 10-20 minutes at a time. The recently added feature of individual accounts is helpful so students can return to their current level/progress through the puzzles rather than starting over or building on work done by others. I assign an account to each pair/trio of students.