This market will resolve when an app is publicly available on any app store for mobile phone. 

Not that it should be an app able to translate from a video stream. The app should be reliable enough to follow and understand a 10min video with only sign language. The app should be able to translate different people at different distance and under different lightning, etc...   Models pre-trained to understand a few words signed by a single individual (such as:

The resolution will be established starting from the initial publication of the post (19 of March 2024) and will resolve to 

  as follow:  if the app is published at anytime between now and 18 of March 2026, the accepted answer will be two years, between 19 of March 2026 and 18th of March 2028 the accepted answer will be 4 and so on. If no app exists after 19 of March 2042 the market will resolve to  more than 18 years  .