When it comes to User interface prototyping, you will find loads of solutions, some of them web based with limited features, others non-free, etc. None of which I was happy when short on money, or say for an occasional project.

But I have finally found a quite good solution.

Here is Pencil, free, open-source with all the features I was expecting:

• Templates, so you don’t repeat yourself
• Built-in Native UI elements
• Image import
• Export to PNG and PDF

If you are an iOS guy, the common iOS elements are also directly embedded in the app.

Note that if you run on Mac OS Mavericks, you will need the version 2.0.6 (in beta at the time I am writing this).

That’s it, give it try and enjoy.

Pencil project