Dual channel function/waveform/signal generator for the speaker/headphone audio output. Educational use, for critical applications use a real calibrated function generator.
Educational Function Generator Demo

Output will depend on your device hardware. Some device hardware may may filter out the DC bias and low frequency signals.
At high frequencies, the waveforms will be distorted due to limited number of samples for each waveform (for example at 4.41kHz, a sine waveform will be approximated by only 10 points).
Either sine, square or triangular waveforms can be selected with the 3 buttons on the left of this section.
This is a single screen app with two displays at the top showing the waveforms for channels 1 and 2 respectively. The output can be turned on with the blue button at the bottom right. The left and right audio outputs can be assigned to either channel 1 or 2 and turned on or off in this output box.
(This app has not been tested completely by me, looks interesting and useful for learning)