1. Green Gas Pedal: Touch the gas pedal to automate RPM (Revolutions Per Minute). You can also drag the green dot on the gas pedal clockwise. 2. Green RPM Text: Crank Revolutions Per Minute. Touch the text to switch to RPS (Revolutions Per Second). 3. Purple Piston Speed Text: Instantaneous speed of the piston. Touch to cycle through various units 4. Piston Speed Text: Touch to switch to position text 5. Blue Connecting Rod: Touch the rod to change length units 6. Red Crankshaft Radius: Touch the crank to change length units 7. Gold Key: Touch the key to start/stop the piston 8. Black Clockwise Button: Changes the rotational direction of the crank 9. Orange Piston Slider: Becomes visible when yellow key is turned off. This allows you to manually adjust the crank angle. 10. Green Slow Motion Slider: Slows down the apparent motion of the piston. Does not affect the simulated speed formula. 11. Blue Rod Slider: Change the length of the piston rod. 12. Red Crank Slider: Change the length of the crankshaft radius.