Novocall - Novocall converts web visitors into sales calls in seconds.
Cal.et - Add to Calendar Link Generator
OptinMonster - OptinMonster helps to convert abandoning website visitors into subscribers and customers.
Microsoft Outlook Calendar - Calendar is a time-management web application by Microsoft.
Callpage - Turn website visitors into sales calls. Use CallPage and provide immediate free phone callback to your leads in 28 seconds.
AddEvent - AddEvent is an Add to Calendar button for one-time and multiple events.