I'm using the SfNumericUpDown control. I added all of the listed required references to all of my projects, and I also performed the iOS setup of instantiating the renderer inside the FinishedLaunching override.
The control works great on Android and UWP.
On iOS functionally it's also perfect, but the spin button size is TINY.
Tested on iPhone 6S Plus (real device)
and on iPhone 6S (Simulator)
Here is a screenshot of how this looks:
Any help is much appreciated.