Single post in Browser-specific features (previously Chrome-only)

It looks promising, but whenever I try to open it it first prompts 'Extensions, apps and themes can harm your computer. Are you sure you wish to continue?', and then the download briefly (less than half a second, nowhere near enough to drag to the extensions bar) appears before disappearing again; the top bar now says 'Apps, extensions and user scrips cannot be added from this website.' May I suggest uploading it to the Chrome Web Store? EDIT: Got it downloaded - go to the little square-of-9-squares in the 'start' bar (this is probably only for Chrome OS), second page 'Files'. Drag and drop onto the Extensions page, follow instructions thereon.