As Nick said a web interface is being looked at and we’re assessing the viability of it, but we’ve said from the beginning that we’re aiming to be a mobile only bank for the moment so such a thing is a fair amount of time away (if it happens).
Were such a thing to happen it would probably not be a fully featured interface and more of a portal to freeze cards or log your phone out, at least for a first iteration!
As Christophorus said though, the next release of the API will likely give rise to a number of community built apps for various features across all platforms!