Shows the zero-based character count at the cursor's position, '940' in the picture below.
Only visible while editing, just like other features in the status bar.
You can search for and install this package in Atom, or using command line:
apm install status-bar-cursor-position
Issues, suggestions, and contributions are welcome. You can submit a PR or just post a helpful snippet in the issues section.
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.