Text library and expander
Simple Snippets is the easiest text snippets app you will ever use. Simply add frequently used text phrases such as emails, names, addresses, etc in the preferences window and use a customizable keyboard shortcut (defaults to Option+S) to popup a menu with all of your text snippets right next to your mouse pointer. Then, just pick one of the text entries to automatically type it into any running application.
Your snippets are automatically synced to any other devices using your iCloud account. So you don't need to re-add snippets on multiple computers.
If you work with a lot of text snippets, you can either add separators using a newline between snippets. Or for more advanced usage, create groups by adding a ">" prefix and then add snippets under them using the ">>" prefix. E.g. ">Emails" for group name and ">>firstname.lastname@example.org" for the snippet.
Simple Snippet is purposefully built to be lightweight and consume the least amount of resources on your Mac. The app is built natively for Apple Silicon with an emphasis on performance and low-resource utilization.