ZenTabs atom package
Keep your opened tabs below a maximum limit, closing the oldest one first.
Inspired by travmik's SublimeText ZenTabs package.
See it in action with a 5 tabs limit:

Pin tabs
You can right click tabs to pin/unpin them. It basically works as a whitelist.

Options
maximumOpenedTabs:5: the maximum amount of tabs that will be keep openmanualMode:false: disable automatic tab closing but still allow you to cleanup tabs through the key bindingsshowPinnedIcon:true: Show a lock icon next to pinned tabs titleneverCloseUnsaved:false: If set to true, unsaved files won't be closedneverCloseNew:false: If set to true, files with anewgit status won't be closedneverCloseDirty:false: If set to true, files with amodifiedgit status won't be closed
Key bindings
zentabs:cleanup, default alt-shift-t: triggers a tab cleanup