I like that this software can detect if it's an Android or iOS phone, which makes testing apps more simple when developing for multiple platforms at once! It also detects OS version so you know what features are supported by your users' devices. The only thing i dislike about Mobile Detect JS is its price tag; however with how much of the market share these programs have now we shouldn't complain too hard because most people don’t mind paying to get things done correctly :) Overall great product but be prepared pay up front otherwise some cheaper alternatives may come out in time ;) We use this tool as part o our app development process where there needs to many different versions (iOS / android). This helps us build all apps from one project without having separate projects each targeting specific phones/os types.