STEM Sandbox

Most STEM apps hand a student a video to watch. STEM Sandbox hands them the controls instead. Six middle-school physics ideas - forces and motion, simple machines, energy transfer, basic circuits, gravity and free fall, and waves and sound - are each a small simulation a student runs themselves: drag the push on a box and watch Newton's second law decide what happens next, move a lever's fulcrum and feel a small force lift a big one, pull a pendulum back and watch its height turn into speed. Nothing here is pre-recorded. Every number on screen - the force, the acceleration, the torque, the current, the wavelength - is computed live from the same equation a textbook would use, so a student can check the app's arithmetic rather than take it on faith. Each lesson opens with a short, plain explanation of the one idea it's built around, then the simulation itself, then a three-question check to catch the difference between watching something move and understanding why it moved. The check is deliberately small and low-stakes - a personal read on understanding, not a graded test, and nothing about it is sent to a teacher or a school system. A student's own progress through the six lessons stays on their own phone. STEM Sandbox makes no network request of any kind. Every simulation is drawn and calculated on the device itself - nothing is streamed, downloaded, or fetched - so it runs exactly the same in a classroom with no signal as it does anywhere else. There is no account, no login, and no advertising.