Publish posts automatically to Twitter.
Good plugin, does exactly what it says. It's a bit of a faff to setup but well worth it to avoid going through third parties (and all the tracking etc. that goes with that) as certain other similar plugins require you to.
So why not more stars? Well the settings page is a mess, full of attempted up-selling, and it makes a nuisance of itself with intrusive styling on your plugins page too.