TidyCal

It works and it's cheap, but it’s advertised as white-labeled — which is not true! You still have the Tidycal logo in emails, confirmation emails, and an outbound click link placed higher than important information for your client. PLUS, even when you embed it on your site, it adds a clearly visible Tidycal logo beneath the element, breaking your brand colors, design, and brand presence. It’s not just a logo and outbound click button — it can easily guide your hard-earned potential clients away from your site. Terrible scam.