When downloading the android iCampsites APK from Outdoor Bits using Opera you may find it being saved as a ZIP file.
This is because Opera interperuts the APK file as a ZIP file due to the MIME Type in the APK file and Opera then enforcing it.
To get around this problem either use an alternative browser or change the file type from ZIP to APK in Windows (see below).
In Windows 7 you will need to click on the start button (Windows button – Bottom Left) type Folder Options and click on Folder Options, then the Folder Options Window opens. Click on the View Tab and scroll down in the Advanced Settings pane and untick “Hide Extensions for known file types”. And click Apply.
You can now remove the .zip on the end of the file name when renaming the file.