When I originally developed the support for Firefox OS web apps, packaged applications could be installed without any issues. But it seems that since then the Marketplace has changed the way it detects what kind of device is used to view it's content. The reason they have done this change is to properly detect Android devices and block packaged apps from being available (hosted web apps can be installed on Android using Firefox Aurora).
To make up for this inconvenience, I'll shortly release an updated version of Hydra and the Marketplace widget that the Marketplace once again recognizes as a genuine Firefox OS device. In addition to that, packaged applications are getting support for automatic update detection (see the teaser below).
|Updates will be indicated in the Hydra manager app and device notifications area.|
|Updates will be fully supported for packaged Firefox OS web apps.|