The error message that ruins the post-PC experience
Whenever I see that red badge on the App Store icon on the iPhone or iPad, I know there are updates waiting to be installed. Over the last weeks I've been facing the same silly error when I try to download apps from the App Store to the point of sitting down, doing some research and try to fix it. I seriously don't know what the "Unable to Download Application" error means when I try to download apps from the device itself directly instead of transferring from iTunes.
A quick Google search and some browsing in Apple Communities shows I'm not the only one. This has been happening to users since June this year. Maybe something to do the iOS version we're running? I don't think so, as it previously worked fine.
The next part of the investigation has to involve the connection. I've recently changed my WiFi router to a different location, so this could be related. I decide to check on my iPhone over 3G, but the issue persists. I know whatever is triggering this isn't just related to the broadband speed.
I have finally managed to get around this issue for the time being following some simple steps. Again, I must admit I have no idea of what's happening — yesterday I managed to download Gameloft's Dark Night Rises big app over WiFi without any problem. These are some steps that have helped and don't require much.
App Store bandwidth
Perhaps Apple servers are saturated certain days at certain times. You don't lose anything trying to update your apps before going to bed or during breakfast and see if there's any difference.
Restart the network settings
This is something I do every time I get poor cellular coverage or when my iPhone or iPad don't want to understand there's WiFi at home for them to use. Simply navigate to the Settings app and toggle the airplane mode to reset the network easily. This should make iOS start from scratch. Restarting the device has also helped, but I'm not sure if this is related at all.
Delete apps to be updated and download fresh
The most annoying thing about this "Unable to download application" epidemic is that the app about to be updated will enter a state where you cannot launch it nor download it. The familiar blue window will ask you to Retry or dismiss with a Done. In my case, I decide to read on Instapaper while the rest of the apps download but… Surprise! I cannot launch the app in that greed out state. Deleting the app and downloading it again (green install button) is a tedious workaround for this.
Whatever Apple is doing to refresh the App Store in iOS 6 will hopefully make this less of a pain. I can't wait to see if that actually changes anything.