I’m not saying Track was the best thing that Twitter ever released, but it was probably the best thing Twitter ever encouraged early on with its open API (before the Dark Times when Twitter decided to pivot to an advertising company).
Say goodbye to Fleets, the row of fullscreen tweets at the top of the Twitter timeline that expire after 24 hours. The ephemeral tweet format is shutting down due to low usage after launching widely just eight months ago.
Source: Twitter is shutting down Fleets, its expiring tweets feature – The Verge