Lobbyphone is a text message bot that sends legislator phone numbers right to your phone.

Text a postal address to (520) 200-2223 and the bot will text you right back with the names and phone numbers of your state and federal representatives.

I launched it in November 2016 and as of May 3, 2017 it had responded to over 440,000 texts.

You can read how it works, contribute to its operation, or download the source code.