Here are two way of how to delete apps on iphone 7.
Touch X mark
Gently touch on the app icon you want to delete for few seconds. The X mark appears and now you can delete or move the app. If you touch on the app icon little firmly then the 3D touch options will pop out instead of the delete and move options.
Go to Settings -> General -> Storage & iCloud Storage -> Manage Storage and then under Storage choose your app to delete.