I've been running a video game collection site for years. The number one request I get from people is to build an app. I've worked so hard on making the mobile version of the site to be just as functional as the desktop version, and I don't really understand why people want an app over just using the web version. I sometimes wonder if I should just do it to see if I'm missing out on market share, but I don't really want to have to maintain two different user interfaces.