Splitwise - Splitwise is a free tool for friends and roommates to track bills and other shared expenses, so that everyone gets paid back. On the web, iPhone, and Android!
Koalendar - Free Online Appointment Scheduling Software
Tricount - Manage and share expenses with friends
Square Appointments - Add an online booking link. Easily embed the customizable widget directly on your website. Any changes to your online scheduling, prices, or services update automatically.
SplittyPie - Create event, add users and their expenses.
With You and Me - Create a page that accepts appointments easily:1.