What are some alternatives?
When comparing Sine and Envoy, you can also consider the following products
The Receptionist - The Receptionost is a visitor managemnt solution that has visitor logging system to track visitor traffic.
TractionGuest - A smarter welcome for your visitors.
HarmonyPSA - HarmonyPSA - Professional Services Automation (PSA) for IT Businesses
SwipedOn - SwipedOn is a smart but simple visitor management solution. Our paperless gateway makes connecting people intuitive and easy.
JOnAS - JOnAS is a leading edge Java EE 5 certified Open Source OSGi Enterprise Server by OW2.
WhosOnLocation - WhosOnLocation is a visitor management system that makes it easy for reception teams and/or non-manned reception areas to know their visitor.