OpenDocument Reader - view ODT 4.13.0

Saving is safer. A failed save no longer leaves the original file damaged, and saving a document that got shorter no longer leaves part of the old file behind, which could make an .odt or .docx stop opening. A file we recognise but cannot open now says so directly, with a way to get in touch. The upload offer stays for formats we do not support at all. Audio and video files handed to the app now play. The review prompt appears far less often.