GivePulse
8.1#1 in nonprofit volunteer management softwareFrom $1.75 a yearFree planAndroidiOSWebAPI
VisitIt suits organizations coordinating volunteers and tracking participation, including higher education institutions and enterprise or CSR teams. The mobile apps and web access support users on different devices.
It suits festival and community-event organizers willing to run and maintain a self-hosted web application. It may be useful where volunteers need self-signup and organizers need role-based access or certification review.