Pencil is a standalone app that lets you create diagrams or UI mockups. It doesn't have collaboration/multi-user features.Discontinued
The last release/commit was in October 2019.
Wireflow is free, online, real-time collaborative, open source tool for creating beautiful user flow prototypes.
Diagramo is an online flowchart software
- diagrams (create, edit and share)
- organization charts (create, edit and share)
- network diagrams (create, edit and share)
- graphs (create, edit and share).
Napkee makes your Balsamiq Mockups come alive. Import a BMML and export to web or flex code in a few clicks.This app doesn't have any features at the moment.Discontinued
The program seems to be no longer updated. Last version, 2.0 alpha 3, released on October 30, 2013, can be still downloaded from the official website.