GiveForms lets you seamlessly embed a form on your website, allowing visitors to donate using credit card, PayPal or ACH, without being redirected away to complete their transaction.
Dudle - Dudle is an online scheduling application, which is free and open source.
Charitable - A WordPress donation plugin that gives you full control over your fundraising experience.
Appointment Booking Calendar - With the Appointment Booking Calendar you can accept online bookings from a set of available time-slots in the calendar.
Give - A WordPress plugin for easily collecting donations
Pulse 24/7 - Booking & scheduling mobile app for service providers
FreeFunder - Free crowdfunding platform with no platform fee and donates to your fundraiser based on shares!