Pencil is an open source GUI prototyping tool which lets the user design user interface mock-ups and diagrams, quickly and easily. The current stable release of Pencil is 2.0.5. It is available on all leading desktop platforms in their native installation formats and even as a Firefox add-on.
Evolus Pencil is available in the software repositories of Fedora and ArchLinux, so users can install it using the built-in package manager. On Mac OSX and Windows, the user can download the bundle and Windows installer from this link.
Installing Pencil as a standalone application
To install on Fedora, RHEL and CentOS, type:
$ yum install -y pencil
To install on Ubuntu and Debian, type:
$ wget http://evoluspencil.googlecode.com/files/evoluspencil_2.0.5_all.deb $ dpkg -i evoluspencil_2.0.5_all.deb
To install on ArchLinux, type:
$ yaourt -S pencil
When a user starts the standalone Pencil application, it looks simple and intuitive.
In the main windows, it contains a toolbar and a working area with a floating panel for collections of various components.
Pencil provides components for designing native UI widgets. The user can fine tune application prototypes using various options such as Group, Ungroup, Style, Arrangement and many more provided in the right-click context menu of the canvas.
Pencil as a Firefox add-on
You can use Pencil as a Firefox add-on via the Mozilla add-on page.
Designing Android applications using Pencil
Pencil provides stencils and templating options for including custom widgets, which are required for designing specific applications such as Android or iOS apps. A list of all available stencils and templates can be found here.
Download the above Zip collection and import this collection using Tools > Install new collection > Select location of download.
This will import all widgets available in the collection, which can be accessed in the Collections toolbar.
You can also design and prototype iOS applications and Web applications using Pencil stencils and templates, as well as design your own widgets and package them as a collection.
Pencil can export designs in various formats such as SVG, PNG, PDF and even the ODT file format. It is an effective tool, which can save you money as it is free and open source. Also, developers become less dependent on designers.