This DOC to Text is a free and handy utility that can be used to convert MS doc, xls, odt, odp, ods documents to plain text files. This app only works locally without going through the server. It allows you to extract texts instantly, real-time.

You don't need to upload doc, xls, odt to any server. It's very safe, and guarantees privacy.
You can also extract text from many document files with one click. You can select doc, xls, odt files to extract from your local computer and from Google Drive directly. This app contains advertising.
Supported format: doc, xls, odt, odp, ods