To see this in action, here&#x27;s a video: <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=IqxAVGRPow0" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=IqxAVGRPow0</a><p>I based parts of the app on Ringdroid, using its code to do the waveform display and the selection sliders.