AVCaptureSession with multiple previews

I have an AVCaptureSession running with an AVCaptureVideoPreviewLayer.

I can see the video so I know it’s working.

However, I’d like to have a collection view and in each cell add a preview layer so …

How to change the color of an UIImage

I want not to change the backgroundColor of an UIImage,
but rather to change the color of the whole image.

Because I have got standard forms which I can move from popover to the view.
In my App it is …

How to merge two UIImages?

I am trying to merge two different images and create a new one. This is the way I would like to do:
I have this image (A):

It’s a PNG image and I would like to merge this one with another image (B) …