Amazon Drive's unlimited plan first launched in the US last year, not long before iOS and Android apps arrived to make the service a serious competitor to the likes of Dropbox, Google Drive, Box and others. It's also accessible through browsers and dedicated Mac/PC programs. There's no Prime favouritism here -- anyone with an Amazon account can sign up for the £55 yearly unlimited plan, and most will be able take advantage of a three-month free trial to get themselves settled in.