Affinity document
AF is the single document format of Affinity 3, which brings photo editing, vector design and page layout into one app. It replaces the separate .afphoto, .afdesign and .afpub files of earlier versions, and stores layers, vector shapes, text, pixel layers and settings in one archive. ToAny reads the preview picture Affinity saves inside the file, so what you get is Affinity's own render of the document, at the size Affinity stored it (up to about 512 pixels on the long side), not the layers or the full-size artwork.
Opens in Affinity 3; not other design tools
AF converter