I like your question. I had also been pondering a full post on the benefits and drawbacks of mobile apps for local governments and just posted a new blog. I agree with some earlier posters that it depends on the function, but I don’t know how the app developer you spoke to picked 200,000 population to make a separate mobile app per focus. I don’t see how that would do anything to help the app’s function or usage. I discuss the design element in my post, Mobile App Design and Organization.