BetterStickies (Free)

Desktop sticky notes that stay visible while you work. Stick images, GIFs,
files, folders, or anything to your desktop. Fast, offline, ~75MB.

Common Use Cases:
• Stick images & GIFs of loved ones, memes, or decorations
• Organize desktop files and folders into small renamable links
• Keep notes and to-dos always visible above other windows
• Set reminders with desktop notifications
• Paste anything inside notes (text, code, images, files)

Features:
• Fully customizable: font, color, size, background images/GIFs
• Drag files and folders in, rename them, drag them back out
• Hover over images and PDFs to quick preview them
• Automatic code detection when pasting (~50ms)
• Snap to grid for organizing stickies on desktop
• Customize local and global keyboard shortcuts
• Always on top, pin notes to lock position and content
• Export to TXT, Markdown, or JSON — no vendor lock
• 11 languages including RTL Arabic
• CJK input method support (ibus)
• Multi-monitor support

Free version: 5 notes, 1 active reminder, 1 GIF background.
Unlimited at https://betterstickies.com/pricing