Postscript - Like Mailchimp for SMS
Bloomerang - Bloomerang is a simple donor database and fundraising software solution that helps nonprofits decrease donor attrition and increase revenue.
Tatango - Tatango is a mobile messaging platform for agencies.
Kindful - Nonprofit donor database + fundraising tools all in one
Flowroute - Flowroute provides direct access to telephony resources - such as calling, messaging (SMS & MMS), call routing, SIP Trunking and Communication APIs.
Classy - Expressive, flexible, and powerful stylesheets for native iOS apps