There are a lot more! The developers should be aware of the latest development technology in the market, and should understand what people are demanding currently. It's important for everyone to know that there is no point in designing a value-less app. Try building good apps and then get them listed in the app store. There is no restriction in thinking ideas that fall outside of gaming category. Anything that can provide value to the customers is the idea that can be converted into an app. So, then be it just designing a banking app, private chit-chat box, or anything. More important than developing an app is its marketing strategy. Only a good marketed app can reach to millions of users out there on the internet.
First step is to promote the product aggressively in the market. Marketing is a tricky technique that requires efforts, sympathy and empathy, but once you start rolling, things would fall into places automatically. A good iPhone development company in India along with good developers, have a marketing team solely responsible for promoting apps and websites. With their abundance of experience in advertising, they can make your app reach out to those all looking for the services similar to sold by you.
Once your app has gotten into the market, and if it's really built on a good idea, the only thing you'll observe after building the app is growing number of downloads!