https://www.ls.graphics/ (featured)
https://design.facebook.com/toolsandresources/devices.html/
https://www.freemockupworld.com/category/ui-ux/
https://www.ls.graphics/free-mockups
https://www.behance.net/gallery/91364315/Cartoon-Mockup-free-mockup?tracking_source=search_projects_recommended|free iphone mockup
https://www.semplice.com/supply
https://www.behance.net/gallery/101781951/iPhone-Screen-UI-Instagram-Mockup-Creator?tracking_source=search_projects_recommended|iphone11
https://dribbble.com/stories/2020/10/29/free-design-mockups-templates-icons