Greasy Fork is available in English.
Shows an inline lightbox for images instead of opening a new tab/etc.
This is basically IMGXIS for TweetDeck - its lets you get a close look at images, GIFs, and videos without having to open them in a new tab and/or having to save a local copy.
Effects:
For each case, you can press Esc to close the thing or click on the underlay to do so (like with profile popups, really).
