PopClip is a Mac utility tool that pops up with a menu of actions when you select text on your screen. Screenshot of PopClip
PopClip's actions range from simple copy-paste and web searches to complex tasks such as translating text. Using extensions, you can add more actions to PopClip to adapt it to your needs. Think of PopClip as a context-aware assistant that provides a set of tools you can use instantly in any app.
PopClip is available for macOS only. It is a paid app with a free trial. It has been in continuous development since 2011.