I went with AddToAny, as it had the most installations, is entirely open-source, and offers all the functionality I need.
====Avoiding JetPack====
I tried to add a profile picture, but by default, WordPress uses [https://en.gravatar.com/ Gravitar], which, surprise, surprise, links to your WordPress.com account... and to add a self-hosted site, you have to install JetPack. At this point, I felt harassed and doubly so because I didn't install JetPack and yet, some how, the profile picture correctly updated from the one I'd posted on Gravitar. What the hecK?
===HTTPS===