Titan Text Expander™ od TitanPlugins.com

Titan Text Expander lets you save frequently used text snippets and insert them anywhere on the web with a simple shortcode.

How it works: Create a snippet with a shortcode (e.g. support), then type --support in any text field, textarea, or contenteditable area on any webpage. The shortcode automatically expands into your saved text — rich formatting included.

Key features:

Rich text editor — Create snippets with bold, italic, headings, colors, and bullet/numbered lists using the built-in Quill editor
Universal compatibility — Works in standard text fields, Google Docs, Microsoft Office Online, TinyMCE, Slate.js editors, and more
Quick access popup — Search, sort, copy, or insert snippets directly from the toolbar popup
Full management page — Add, edit, duplicate, delete, import, and export snippets with the dedicated options page
Instant search — Filter snippets by shortcode or content in real time
Cross-device sync — Snippets sync automatically across your Firefox devices via Firefox Sync
No data collection — All snippets are stored locally in your browser. Nothing is ever sent to external servers
Import/Export — Back up your snippets as JSON files or transfer them between devices
Shortcode rules:

Type -- followed by your shortcode (e.g. --hello, --email, --address)
Shortcodes cannot contain hyphens or spaces
Rich text content (HTML) is supported
Privacy: This extension does not collect, store, or transmit any personal data. All snippet data is stored locally in Firefox's built-in storage and optionally synced across your devices through Firefox Sync, which is encrypted end-to-end by Firefox.