280 Twitter Counter Extension adds the character counter into your tweet form, warns you about the 140 character limit and provides the opportunity to show or hide the circle.
The extension is compatible with TweetDeck and standard Web Client.
If you prefer to build the extension from source code, First things first, we should install the project dependencies:
yarn install
Then build the extension:
yarn run build
It creates a directory called "build". After that, using the official Testing and Debugging guide, pack the extension. Done.
Please, feel free to ask any questions that you have about using and developing the extension.
Good luck.