OnDevice App is responsive tester made in collaboration with a full-stack developer colleague to create a comprehensive solution for checking a website responsive behavior as well as being able to present this behavior to the stakeholders in an appealing way.



OnDevice is an interactive web application that displays the requested URL in the list of selected device mockups within a horizontal testing area. Being compatible with Chrome, Firefox, IE, the application is offering about 50 devices from mobile to HD desktops to be selected for testing. Available functionalities:

  • loading and displaying HTTP / HTTPS domains
  • loading the same url in multiple device mockups at the same time
  • live, clickable website preview
  • choosing from the device list by type, market share, physical size, screen resolution
  • scaling down devices within the testing area
  • adjusting scrollbar width
  • adding custom agency header for presentation
  • remote presentation with screen share
  • top+bottom scrollbar
  • device rotation
  • retina ready display
  • devices mockups displayed by their actual physical size


Built on a custom framework written in CommonLisp computational language, the application is fast, steady and lightweight. The remarkably short page load time ensures high testing capabilities even when great number of devices are selected for testing.


Linux server

SSL port

Responsive framework

CommonLisp / CSS / HTML





During the project planning phase all the ideas got written down and compared with the currently available solutions on the market.  To build up the product identity, several user personas and messaging styles were created and tested as well as the planned functionalities has been benchmarked. What have fallen together during the industry research served as a basis for the digital marketing strategy plan. In order to prioritize the functions planned to be developed the first roadmap has been created, listing the features based on their place and importance in the audience workflow. When the first set of functionalities for the MVP reached agreement the development work has started. The product architecture followed the click flow mockups and once was ready, applied the detailed final branding strategy.


Application website: ´╗┐




When the MVP was ready and tested for quality assurance, the product went live and the promotion work has started. Numerous micropages has been created to introduce the problem and to describe our solution. Also, several educational articles has been released about the technical matters of website responsiveness. Parallel with the copywriting effors the digital marketing strategy has been launched on the chosen social channels using branded materials and automation tools. Along with the marketing efforts, the technical side of the project required the implementation of a more advanced solution for handling the payments and maintaining the device library.




Due to our personal engagement the project maintenance has been paused for a while. Currently we're reorganizing our sources to be able to keep maintaining the product, expand the device library and continue with the marketing efforts.




Planned features:

  • allowing switch between editor view and test view
  • ensuring draggable screen size in the editor view
  • allowing to add custom breakpoints
  • allowing to create custom device folders for recurring testing patterns
  • enabling linked scrolling between the device mockups
  • enabling liked rotation between the device mockups
  • inviting viewers into the testing area