Our non-profit builds Councilmatic - https://www.councilmatic.org/ - free & open-source tech for city-level civic engagement. Closing the feedback loop with local government, accessible tools for community dialogue.
But in my ten years' experience, here's what I see as the biggest potential for tech for social good: open data standards for constituent communications. Breaking public messages out of the current silo's of individual e-mails, e-petitions, social media, civic tech apps, and issue advocacy platforms. Making possible open structured data on real public priorities and policy preferences in every Congressional district. This never took off because government offices haven't wanted such a level of participatory democracy, and because existing advocacy groups haven't wanted to share membership lists and enable peer-to-peer organizing - it would undercut the business models of e-petition companies and legacy advocacy vendors and VC-backed civic startups. But making public opinion info more free and open for analysis could push forward reforms that have wide support, and are stymied by the current U.S. two-party system: http://www.participatorypolitics.org/open-data-infrastructur...
Indeed, our non-profit project OpenGovernment.org, launched in Jan. 2011, is still available in open-source code for legislative tracking: https://goo.gl/ThcG00. This includes the GovKit Ruby gem, which aggregates open government data with social context to make legislative info more accessible. We're always looking to re-boot OpenGovernment.org (OG for short) to focus on contacting state-level elected officials and discussing issues in the news on the open web - more about our goals of open data at every level of gov't: http://opengovernment.org/pages/about.html. And yes, as Derek said, check out Councilmatic for city-level transparency and engagement.
But in my ten years' experience, here's what I see as the biggest potential for tech for social good: open data standards for constituent communications. Breaking public messages out of the current silo's of individual e-mails, e-petitions, social media, civic tech apps, and issue advocacy platforms. Making possible open structured data on real public priorities and policy preferences in every Congressional district. This never took off because government offices haven't wanted such a level of participatory democracy, and because existing advocacy groups haven't wanted to share membership lists and enable peer-to-peer organizing - it would undercut the business models of e-petition companies and legacy advocacy vendors and VC-backed civic startups. But making public opinion info more free and open for analysis could push forward reforms that have wide support, and are stymied by the current U.S. two-party system: http://www.participatorypolitics.org/open-data-infrastructur...