iWork for iOS

I purchased iWork from Apple for my MacBook Pro about a year ago and have been using it without any issues. I didn't purchase iWork from the AppStore but rather received it in the mail. I have an iPhone and now would like to have it on my iOS device but it says I need to purchase the app. Do I really have to purchase the app for my iOS device? I read on the apple website that if I purchase one then I can use it on all Mac devices. Any ideas? I checked the AppStore on my computer and it says I don't have the apps but I can load them no problem.