I think Calendly is easy to use and I really like how it is automated to send reminders etc. I find that more people show up on the calls because of the follow ups.

the easy way to register and implementation and a lot of functionalities to individualize

Calendly has been helpful for scheduling meetings without going back and forth over timing. I started using it a few months ago, and the feature I use the most is sharing booking links because it makes it easy for others to choose an available time directly. It saves time, keeps meetings organized, and reduces confusion in scheduling.