Language Tool offers a public version to use. Yet, the SpellCheck-Plugin will work fastest when you use your own local LanguageTool-Server.
For Installation:
- Download: https://www.languagetool.org/download/
- Install LanguageTool as shown here: http://wiki.languagetool.org/http-server
(Please note: "For security reasons, the server will not be accessible from other hosts. If you want to run a server for remote users you will need to use the --public option.") - For Ubuntu, additional information is shown here: https://wiki.ubuntuusers.de/LanguageTool/
- For using the public version, see here: http://wiki.languagetool.org/public-http-api
- Install and activate the SpellCheck-plugin as shown here: Plug-ins: Installation and activation