Mouse double click to mark words (Version: 3.8.82)
You can switch off it on the setting page of Dashboard if you think it disturbs you.
Update date: 2020-06-11
Youtube Videos Subtitles/CC (Version: 3.8.80)
Learn English words while watching Youtube videos. Just move your mouse cursor on the subtitles to mark the words that you don't understand. The marked words are also auto-marked on subtitles/CC.
Update date: 2020-06-02
Email Reminder (Version: 2.7.78)
You can review the marked words with everyday email reminders.
Update date: 2020-05-14