CircleSine is an educational app distributed with the following License.
Creative Commons Attribution-NonCommercial 4.0 Unported Legal Code
Suggested Credit Line: Courtesy Chester/Ruiz

Thanks to code contributions from Ethan Chester, Umar Hansa, and w3schools.com.

Author's Website: www.mjtruiz.com

Instructions
Pause/Start toggles stop and go for the revolving red bead.
Center - centers the little blue circle.
Drag the Ruler to make measurements.
Amplitude - is controlled by the upper slider or A buttons.
Wavelength - is controlled by the lower slider or λ buttons.

Suggested Learning Activities.