Google Calendar lets you organize your schedule and share events with co-workers and friends. With Google's free online calendar, it's easy to keep track of your daily schedule.

Artichoke is a business platform for freelancers: everything in one place, on any device, wherever you work. A web page for booking online, automated reminders, one-touch payments, searchable progress notes, and simple solutions to take control of the numbers for today’s freelancers.

Single connection to all major calendar services: Apple, Exchange, Office365, Live and Google

Cogsworth is an appointment and meeting scheduling app that allows people to book in time with you and your business when you are available. Cogsworth syncs with your calendar and pulls out your availability and also pushes your bookings back to your calendar.

Retrograde is a Zapier-built app that takes the guesswork out of communication during tricky astrological times.

For appointment-based businesses, Apptoto offers automated SMS text, email or voice reminders and online scheduling

Plann3r allows you to schedule any kind of meeting on your highly customisable meeting page.

Chili Piper helps businesses help their buyers. Book or connect your prospects in real time from web forms.

MashApp allows you to automatically track your marketing campaigns and sales results in a calendar.