This is where the concept of modular devices come in, and it seems that this could be something that Apple is exploring for the Apple Watch. This comes in the form of a recently-discovered patent where it suggests that maybe in the future, the Apple Watch could come with user replaceable modules that will let them customize their watch and its functions according to their needs.
The patent’s description reads, “The modular configurations allow a user to easily customize a watch with one or more functional modules to provide features that integrate with other operations of the body of the watch. The functional modules can be easily exchanged with each other to provide different components and functions at different times.”
For example, users who are more into workouts can add certain sensors and modules that are fitness specific. It could also be tailored to meet certain medical needs, such as glucose sensors and so on. So far, there have some some attempts at creating third-party accessories for the Apple Watch, although admittedly none of them have really taken off in a big way.
That being said, with this being a patent, there’s no telling if Apple actually plans on making it a reality, but it is a good idea and one that might be worth exploring.