FSMinvite offers two services.
1. FSM events to Microsoft
2. Microsoft appointments to FSM

FSMinviteIn

FSMinviteOut

Transfers Service Assignments and Reservations from SAP FSM Planning Board to Outlook Calendar.

Service Team's calendar in Outlook is updates with their FSM engagements.

Formerly known as SAP FSM for Outlook (SFFO)

Transfers Outlook appointments to
SAP FSM Planning Board as Reservations/Absences.

Planners have a complete view of Service Teams' availability.

The services can be in operation separately.
You can have both or only one as suits your needs.