I went through the process of applying to be a Fellow with them, and made it through the 3rd round. From what I gathered, their objective is to focus on projects that are highly generalizable. That is, they won't greenlight a project that's so specific it only benefits a specific client. They want projects that can be adapted for lots of municipalities. One example I recall was a database that was used to track fire hydrants somewhere. In a general sense, it's a simple inventory type of app where you can track just about anything that's fixed -- like parking spaces, parking meters, signs, garages, buildings, street lights, billboards, whatever. Their developers create open-source solutions with adequate documentation that can be used by others to adopt and adapt the code as needed.
So to answer your question, yes, AFAIK their goal is to ensure that 100% of the work their Fellows do is transferrable to LOTS of other municipalities. That's probably why they call themselves "coding for AMERICA", vs. "coding for Camp Verde, AZ".