Will there be an iOS/Android app or is this just web browser based only?
The first phase is porting all functionality into a new web browser based MapBox interface to utilize lots of MapBox's innovative web mapping technology. MapBox does also include Android SDK's which is the end goal of the second phase. I currently don't own any mac computers, so I have no plans of developing an iOS app at this point in time.
We will use the web interface to port iOS and Android apps so that users can install them on their smart phones.