The Reveal Color View project is a B4A project using the XUI library.
But, it is not cross platform!
Perhaps, the code module used is cross platform compatible.
But as soon as you compile a cross platform module into a library, this library is mono platform!
By the way, when you compile a B4i module into a library you need to ask Erel to be able to use it with the Hosted Mac Builder.
You thought correctly, in fact the library is cross platform as you can deduce from the title [B4X].
You have to download the library in the ios version.