Based on your search query, the Pedagogical tool seems to be the most suitable option. It offers a feature called "Lesson Content Extraction" which allows you to use your existing lesson materials to enhance essay feedback. This feature can be used to extract vocabulary lists from texts, which aligns with your requirement.

Moreover, Pedagogical supports various content types like images, PowerPoint slides, Word documents, PDFs, and YouTube videos, which means you can extract vocabulary from a wide range of sources.

The tool is currently in beta, which means it's still being developed and improved, but it offers a free plan that allows you to extract up to 5000 words. If you need to extract more words, there are upgraded plans available starting from £5 per month.

Please note that as the tool is in beta, there might be some bugs or incomplete features. However, given its potential and the features it offers, it could be a valuable tool for your needs.