In the Workflow Editor are following functions available:

Symbols Functions
Navigation and selection functions
Stat, end and gateways events
Activities
List and details on the activities
Symbol Activity or functions Description and details
Start event Required for all workflows
End event Required for all workflows
Gateway Required in case of different scenarios, for example for the approval process (approved or refused?)
Set reminder
ApprovePage
Page checkout
Page check in
CustomForm
SendMail
UserFeedback
UserVote
GroupFeedback
GroupVote
EditPage
EditRequest
SetTemplateParams

Workflow activities that currently can be included in a workflow: