Smartphones contain sensors that can be utilized to take data and to simulate realistic demonstrations. We have developed simulations and activities that take advantage of these sensors and students’ familiarity with their devices to model systems such as a friction block on an incline and simple harmonic oscillators. We use a web browser to display these systems with annotations, such as force-body diagrams, that respond to device motion and orientation.  These simulations and activities are freely available in the Open Source Physics Collection on the AAPT-ComPADRE website.