Showing a user's contacts in the form of a list is a fine idea. It's functional, looks all right, and people are used to seeing data displayed in the form of a list. However, wouldn't it be nice if there was a more interesting way to display the same contact data? For instance, using bigger images for the contact photos. And instead of showing everything in a list, maybe a grid is a nice alternative.
Exciting and compelling layouts drive user engagement. Users enjoy interacting with well-designed apps, and they certainly notice when you put in a bit of extra effort. Of course, merely implementing a grid layout won't automatically make your app great but when used well, users can certainly feel more at home with your app than they would if you just stick to a table view. Every app benefits from a different kind of design and layout, so collection views are no magical solution for all apps, but they indeed are a powerful tool to master.
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