Be careful with old versions!
These versions are displayed for reference and testing purposes. You should always use the latest version of an add-on.
[*] Toggle private state using tab duplication: try restore text in URL bar (#237).
[x] Fixed private protocol in Firefox 37-43 (caused by `nsIIOService.newChannelFromURIWithLoadInfo(…, null)` failure) (#247).
[*] Updated Indonesian (id) locale, thanks to Muhammad Anwari Ramadhan.
[x] Fixed ability to open new private tab in Firefox 54+ (with browser.newtab.preload = true) (#252).
[+] Added privateTab.replaceTabAndTogglePrivate() API.
[x] Fixed ability to open private:… URI in already opened tab (will be used workaround with tab duplication) (#251).