DashLight by Walrusec

You configure the engines you want to use via the configuration window, and then whenever you highlight text on a webpage, it will present you with a dropdown of those engines. When selecting an engine, the extension will assist you by navigating to that search engine's results page for your highlighted text.

Key Features:
- Customizable search engine list with drag-and-drop organization
- Import/export settings for easy backup and sharing
- Repository of pre-configured search engines to choose from
- Unobtrusive interface that appears only when needed
- https://github.com/walrusec/dashlight-engines