TextBlast Bulk SMS - Send personalized mass messages easily

Muster - Muster is a grassroots advocacy tool that enables professional associations and nonprofits to engage their membership in the legislative process.

LoopMessage - LoopMessage is a perfect macOS tool for personalized mass messaging via iMessage/SMS, WhatsApp, Facebook Messenger, Telegram, Viber, and Skype.

NationBuilder - The world's first platform for leaders, handcrafted from scratch to help you grow your community and lead them to action.

Porterhouse - Send mass iMessage and SMS texts from your existing number with a single click!

NGP VAN - NGP VAN offers an integrated platform that combines the best fundraising, compliance, field, organizing, and new media products.