NHRangeSlider is an open source Swift based UI component submitted by Ngo Hung providing an open source range slider UI component with nice customization options.
NHRangeSlider allows you to customize the color of the slider, have the curvaceousness of the slider thumbs, and add labels above the slider, and the labels for each thumb.
This image from the readme shows NHSlider in action:
You can find NHRangeSlider on Github here.
A nice component for making custom range slider controls.