This is not so much of a feature, but I think that an app, and I know that there are plenty of apps on the Steem blockchain right not, but an app that will merge everything that these small apps are doing into one.
Right now we have Esteem, Steemify, SteemApp, SteemMonitor and many more. My idea is an app that will allow for a smoothly operating posting feature, a notification feature, a non-glitchy feed and tags viewer, a profile manager, a feature that shows the analytical part of the Steem blockchain, similar to steemdb.com for example, and perhaps even SteemChat all in one. Right now we have to jump in between various apps, making it a nightmare to use. It is also slightly discouraging to many new users joining Steemit.
All of this put together into one app that would be available for both iOS and Android would inevitably result in a higher amount of people joining. Most people, some of my friends whom I showed Steemit to, are interested and hooked onto it, but all tend to ask why there is no one Steem app. In an era where everything, and I mean even paying for groceries, is done through smart phones, an app is a must if Steemit is to survive and thrive amongst many other rapidly growing social medias.