osTicket is a widely-used open source support ticket system. It seamlessly integrates inquiries created via email, phone and web-based forms into a simple easy-to-use multi-user web interface. Manage, organize and archive all your support requests and responses in one place...
Freshdesk is an award-winning, online help desk software that allows you to support customers over email, phone, the web or even through Twitter and your company's Facebook page. With Freshdesk there is nothing to download or install, you don't have to worry about server...
ProProfs Help Desk Software is a feature-rich issue tracking software that enables online businesses to track all customer issues, requests, and bugs. Offer timely response to your customers through child tickets.
UseResponse is a customizable Community Feedback and Support Software can be installed on your server as a PHP script or used in Cloud as SaaS.
InvGate Service Desk is a web-based ITIL-ready solution with an unprecedented user interface. offering Incident, Problem, Change, Asset & Knowledge processes. visual workflow builder, business analytics reporting, dashboards, SLAs, email ticketing.
((OTRS)) Community Edition is the free, open source version of OTRS, a ticketing and process automation suite used by service teams to improve communication and customer satisfaction.Discontinued
From https://community.otrs.com :With the release of OTRS 8 at the end of March 2020, ((OTRS)) Community Edition 6 reached its end of support and maintenance. As of January 1, 2021, ((OTRS)) Community Edition 6 will not receive any further security updates.
UserVoice communities are the easiest way to turn customer feedback into action:
Crust Service Cloud is a free, open-source and self-hosted customer service desk, built on the Crust Low-Code platform. It enables businesses to deliver faster and more personalised service to their clients, across multiple channels.
Get Satisfaction is a community platform that helps companies create engaging customer experiences by fostering online conversations about their products and services at every stage of the lifecycle.This app doesn't have any features at the moment.