Napkee is completely free and open source. You can find it on Github here. Feel free to contribute!
Napkee tries to support all the controls you can find in Balsamiq Mockups. We are committed to include new controls or changes to the existing ones as soon as they are available on Balsamiq. Plus, whenever you modify and save a file on Balsamiq Mockups the changes are shown on Napkee in a blink.
Prototyping and testing during the early stages of a project is the key for a successful desktop or web application. This is the ultimate goal of Napkee. See a working example of the Bootstrap HTML export of the mockups seen on the screencast.
You are in good company More than 1000 companies, NGOs, associations and individuals have chosen Napkee
"Today I debuted the napkee-based Flex prototype as part of a follow-on meeting with the users for some new features they wanted us to build. We had some different ideas come up as we were talking. So I made some mods to the mockups, since napkee is always in sync, I simply re-exported the latest napkee files. Flex Builder detected the source code changes. I re-started the flex app and in a matter of minutes, we were looking at our new ideas. "Jon Kern / co-author agile manifesto, agile coach, architect, generalizing specialist
"Napkee offers all the necessary options to make rapid prototyping possible; it allows you to remain in a creative state of mind as you're not bogged down in markup. It has greatly reduced the time between prototype iterations - we're now able to spend considerably more time on userbility testing. Our applications are infinitely better for this! "Rob Willie / User Experience Architect, PrimarySite Ltd
"We build applications for companies marketing themselves in social platforms like Facebook and Twitter, where often clients don't fully understand what's possible until you show them. Using Napkee combined with Balsamiq, we're able to create fully clickable, HTML prototypes which bring our ideas to life, making our proposal and client sign off process radically faster and easier; something instrumental to our current growth."Joshua March / CEO, iPlatform Ltd