Mask is described as 'is dedicated to protect your personal privacy in your smart phone by hiding or encrypting applications, pictures, photos and video clips as well as files' and is an app in the Security & Privacy category. There are three alternatives to Mask for a variety of platforms, including Windows, Mac, Windows S, Windows Phone and Android. The best alternative is Boxcryptor, which is free. Other great apps like Mask are S.S.E. File Encryptor (Freemium) and Perfecto Encryptor (Paid).