So, testing latest image 34, I decided to try installing some click apps.
I started with a very simple webapp (18k download size), and this worked reasonably well. Then I tried installing SleepyTime, which is a few MBs to download. During the download, I accidentally swiped left (eg, to see the previous app, not an edge swipe). When I swiped back to SleepyTime, the download had frozen. After some seconds, the progress meter reverted to an 'Install' button, which was unresponsive.
Then I thought I'd reboot to get things into a fresh state, tried to install SleepyTime again, but this time I thought "ok! I won't touch anything, so it can install uninterrupted!" and of course, then the screen locked while the app was downloading. When I unlocked the screen, the app detail screen was gone and I was looking at the app grid. When I clicked on SleepyTime again, the download meter was gone and there was the 'Install' button again. When I clicked on the install button, it turned into a progress meter, stayed at 0% for about 10 seconds, and then reverted to an Install button again.
So basically, it seems that in order to install an app, I have to very carefully poke at the screen in order to keep it awake, without accidentally navigating away from the download screen. Leaving it alone, navigating away, etc all cause downloads to fail, and once a download has failed, all future downloads can't even start.
ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity-lens-applications (not installed)
Uname: Linux 3.4.0-3-mako armv7l
ApportVersion: 2.12.7-0ubuntu1
Architecture: armhf
Date: Wed Nov 27 19:38:59 2013
InstallationDate: Installed on 2013-11-27 (0 days ago)
InstallationMedia: Ubuntu Trusty Tahr (development branch) - armhf (20131127.1)
SourcePackage: unity-lens-applications
UpgradeStatus: No upgrade log present (probably fresh install)
The problem seems to be that the download is started, which when it's finished will cause the app to be installed, BUT the scope is not checking whether the app it's displaying on the preview is being downloaded.
So, when the preview is refreshed (for example, because you navigated away), you get "Install" and no process, even though the app is being downloaded already.