Creddon - Tweet for a cause and a sponsor will donate $1 to charity
Anedot - Powerful giving tools made easy for everyone
All or Nothing - Competitive donations for causes you care about.
Tiltify - Streaming. Fundraising. Interact with your community for the causes you are passionate about.
Public Design Vault - 500+ design tools for public good, all in one place
GivingTools - GivingTools is one of the high-class websites that aid you to make your own fundraising sites for easy online donations and have the ability to cover the processing costs, making you maximize productivity.