Custom or alternate watch faces

Why hasn't apple taken advantage of the nano clock face feature?!?! Its seems like everywhere you look a new watch band is being made for the nano, yet we only have 2 faces to choose from. Apple needs to create "clock face apps" for the iTunes store. Something that would allow developers to create custom "faces". The possibilities would be endless, analog, digital, different colors, or even Tokyo Flash (http://www.tokyoflash.com/en/watches/1/) type watches. I would even be willing to pay for these "apps" if they existed. Come on Apple! You're slacking!