I installed Ubuntu 14.10 just yesterday. Webapps are of the features most advertised in the Wubi Installer. I can see that the Ubuntu browser has upgraded. Unfortunately all webapps show a blank screen.
I would prefer to use Ubuntu's webapps rather than Chromium ones since they are coming directly from the software center with an open source license.
I would like to use gmail, qqmail, livemail and facebook. Considering the feature freeze I doubt there would be a fix for this in this release. Also if they work for your Ubuntu 14.10 (not 14.04) distribution please let me know. They worked in 14.04 version for me. But I prefer the more advanced 14.10 version. The 14.04 webapps were not of a high quality especially the youtube app which almost always caused problems. So to keep it short, let me know if they work in your 14.10 system and let me know if you know what the cause of the problem might be and any workaround.