The Sky Go application will not work for me because it thinks my Samsung Galaxy Nexus is rooted even though I have never rooted it.
According to the Sky customer service agent I chatted to, this can be because of apps on the phone which weren't installed from the Android Market/Google Play.
I know that I have manually installed an apk or two in the past, but I am not sure which apps still on the phone (if any) were installed manually.
So, how can I tell which apps on phone were installed manually and which were installed from the Android Market/Google Play?
 Amusingly, the only app I can remember installing manually was the Sky Go app, when it wasn't available to download for Galaxy Nexus phones. It didn't work however, and I removed it.