I plugged my iPhone into iTunes for the first time yesterday to sync and backup to my Mac rather than to iCloud. However in doing so, I've lost 20GB of space on my iPhone! When looking into the 'Storage' section on my iPhone, none of the individual apps seem to have change. For example, Photos & Camera was the same size before I used iTunes as it is now. Also there are no new apps that have been installed. I am totally confused! Any help?