While I’m not working at Tragnarion Studios anymore (just switched jobs :D) the last project I was the technical lead was a small HTML5 UE4 powered 3D web catalog. I’m not sure if there are many released HTML5 project suing UE4 out there apart from Epics demos. The app is only available in Ikeas Puerto Rico site, so accessing it might be slow if you are not there (it uses Amazons CloudFront, so it should be ok from every where).
Once you are at the landing page just choose one of the ‘Inspirations’, the ‘Eye’ icons are used to travel between ‘cameras’ and the ‘Magnifying Glass’ (if any) is used to go to a detailed view. If you hover over a product you will get a nice tool-tip and if you click a product you will be able to add it to the cart.
Hope you like it!
P.S. The web is missing some English localization I guess