For some years we have PDFKit classes and we have controls for desktop:
Technically the desktop and non-desktop variants both can be used in Desktop projects and the difference is the super class and the event naming (Open vs. Opening).
For next version 23.3, we got these ported to iOS:
All these control host the PDF controls from Apple's PDFKit framework. If you like to configure them, please query the view property to get the PDFViewMBS or PDFThumbnailViewMBS object. There you can configure them and e.g. define a background color.
To load a document, please use the PDFDocumentMBS class. Once you have it, please assign it to the document property in PDFViewMBS class. If you have a thumbnail view related to the PDF view, you can connect them. Please assign your PDFView object to the property PDFView in the PDFThumbnailViewMBS class.
If you need something for Windows, please check our WinPreviewControlMBS control. It can show a PDF document in a Xojo window.
Please try these controls for your iOS applications and let us know how well they work.