When used in a CellFillLinearGradient, a value of 0.0 is at the beginning of the gradient and 1.0 is at the end of the gradient. When used in a CellFillRectangularGradient, a value of 0.0 is at the inner rectangle and 1.0 is at the outer edges of the cell.
Target Platforms: Android 4.4+, iOS 8+
Development Environments: Visual Studio 2015+, Visual Studio for Mac Preview, Xamarin for Visual Studio 4.2+