As of the release in September 2018, SAP Cloud Platform Workflow has a major new feature, namely forms. With workflow forms building beautiful form (Fiori) UIs for workflow user tasks is becoming as easy as building workflows.
A modeled form displayed in SAP Fiori My Inbox
The workflow form editor in SAP Web IDE Full-Stack
Simply enable the workflow service and you are good to go. It is enabled? Great, you are all set. The form editor is available in your SAP Web IDE Full-Stack as part of the workflow editor feature.