WinZip is a veteran app. In the old days, when Internet connections were slow, people compressed files to make them smaller so they'd get to their destinations faster. Internet connection speeds have improved, but the use of file compression continues. These days, when files can be very large, we still compress them from time to time to make sharing that bit quicker and storing easier.
If you are the kind of user who needs to view files from email on your phone, then the chances are you will encounter compressed files. And if that is the case then WinZip, or another app which can extract compressed files, is a must-have. Without such an app you are, quite simply, stuck.
WinZip is full of features. It can connect to cloud storage such as Dropbox and Drive, and will cope with all the main compression types. As well as extracting files it will compress them too, so you can send them economically and make the most of limited handset storage. iOS users can take advantage of integrated AirDrop support. You'll need to buy the full version of the WinZip app for access to more advanced features such as using encryption.
OS: Android, iOS