I've used this for about a year now. Yes, it can be a bit complex to set up initially, but the support is fantastic and they'll help every step of the way.
I'm far from a professional web designer. I built my own site simply because I couldn't afford a $4,000 site. I pay, on average, about $25 per month for BB. It sends out a text and email as soon as someone books an appointment, then it sends them a reminder 24 hours before their appointment, another one an hour before. After the appointment, it sends a follow up email a day later and another one a week later.
It's too bad that others haven't taken the time to fully understand all of the wonderful benefits of BookingBug. I hate seeing that it's got such a low rating!
This is an absolutely wonderful application and if you'd like to see it working, visit my page at: www.mysnowwhiteteeth.com . Click on the Book Online option.
Please don't allow the derogatory comments to deter you from using this plugin. It works, it's not simple, but you can't expect a good program to be completely simple to set up. But I will say, it's completely worth it.