There is the updating history and the list of known problems.
Works on Nightly 20.0a1.
Fixed: Reuse "about:newtab" tabs as blank tabs.
Improved: Menu items in the "History" menu are treated like bookmark items. They are opened in new tabs by this addon.
Improved: Bookmarks can be opened in background tab or new window. To configure this behavior, you have to change the secret preference "extensions.openbookmarkintab.place". 1 = new tab, 257 = new background tab, 2 = new window.
Works on Minefield 3.7a5pre.
Improved: No new tab is opened when the current tab is blank. (If you set extensions.openbookmarkintab.reuseBlankTab to false, bookmarks are always loaded into new tabs.)
"Open in new tab" feature is ignroed for Web Panels (bookmarks should be loaded into the sidebar) correctly.
Fixed: Bookmarklets are loaded in the current tab instead of new tabs.
Hungarian locale is available, translated by Mikes Kaszmán István.