Situations with a slow deployment process has been a big motivator for building Config.ly -- and I've seen it happen at companies with medium-sized eng teams (taking hours to swap values during incident fires), and I know it's a problem _all_ iOS developers have due to the app store deploy process.
I also think there's other value here... For instance having a UI means non-technical folks can update it. A lot of my time as an engineer has been spent making copy tweaks (I've felt existing CMS products were too heavy-weight and difficult to plugin).
Also, having turn-key libraries mean you don't have to copy/paste hardcoded values among many clients (or store on the server build an API for _every_ constant). I'm a big fan of DRY.