What is Bookipi?Bookipi is the free invoice app for small businesses, freelancers and contractors to create invoices on-the-go. Bookipi sends invoices for over 700,000 small businesses in over 179 countries. The app can also be used to create receipts, estimates and quotes. Other features include credit card payments, signatures, reports and invoice customisation.Bookipi x Slack Integration Bookipi’s slack integration sends you notifications when your invoice has been opened and paid. In the notification, you’ll be able to see who and what the invoice is for, as well as how much it is.Why you should integrate Bookipi and SlackFor business owners that spend their time in Slack, this is a perfect way to bring together all your notifications. Your notifications will all be in the one place and you get them delivered to where you spend your time.