CopyslateA floating reference board on a Mac: keep images on top of any app
When you model, draw or lay out a page, the references you are working from should stay in view. macOS makes that harder than it should be: there is no "keep this window on top" setting, so the moment you click into Blender, Procreate or Figma, your reference window goes behind it.
What people try first
Split View shares the screen but takes half of it and only holds two apps. A second monitor works if you have one. Preview and Photos have no always-on-top option. Reference image viewers like PureRef exist for exactly this reason: a window full of images that floats above everything else. The trade-off is that the images have to be collected into it first, by saving files or dragging them one at a time.
A reference board fed by your clipboard
Copyslate has a canvas for references, and it fills from what you already copy. Take a screenshot of a reference and press ⌥⇧V: the screenshot lands on the canvas. Right-click any image in your clipboard history and choose "Add to Canvas", or drag image files from Finder straight in. Click the pin in the canvas title bar and it floats above whatever app you switch to.
On the canvas you move, resize, rotate and flip each image, add notes beside them, zoom in close and undo anything with ⌘Z. Save a board as a .slate file to pick it up later; Finder shows a preview of it.
Mood boards without leaving the app
The same canvas works as a mood board while you browse: copy an image, press the shortcut, keep going. The home page shows a board being built next to a 3D model. Canvas is free for 7 days, then part of a one-time purchase.
Questions
How do I keep a window always on top on a Mac?
macOS has no system setting for it. Apps have to provide their own floating window; Copyslate's canvas does, with a pin in its title bar.
Is there a mood board app for Mac that works with screenshots?
Copyslate's canvas takes your latest screenshot with ⌥⇧V, images from your clipboard history, and files dragged from Finder, and it floats over your other apps.
Can I save a reference board and reopen it?
Yes. Copyslate saves boards as .slate files, with the images, notes and layout, and Finder previews them.