I've released a simple add-on that helps collect errors (grammar, style, word confusion) one finds on the web:
The idea is that a lot of people read a lot on the web, and from time to time they spot an error. Whether it's one already detected by LT or not doesn't matter. Typos aren't really interesting, unless the incorrect word is a valid word by chance. If we all collect the errors we find, we get a nice error collection over time. If you also spot errors from time to time, please use the add-on to submit them. Note that you'll need an account at https://languagetoolplus.com which you need to configure in the add-on the first time it opens.
This is the first version of the add-on and I'm looking for feedback on how to improve it.