ToneShaper

Create cycles with tone shapes of smoothly varying frequency by plotting frequency at specific times.
Tap the library button to pick from a selection of sample tone shapes to get started.
Tap in the plot view to add points with coordinates (frequency, time). Drag to move points, but limited by the neighbors time.
Alternatively, drag in the draw tab to add points, then apply them to set the points in the plot view.
Adjust the frequency range slider to limit the bandwidth.
Adjust the duration slider to specify the cycle period.
Finally, in the export view you can save the audio to a WAV file with a chosen number of cycles. The duration of the audio is limited by the maximum duration, which therefore also limits the number of cycles in the audio file.