There’s huge buzz around Spotify’s plans to launch Android and iPhone apps, but the company is unsure whether the latter will even be allowed onto the App Store.”We really don’t know if Apple will give us the go-ahead, and all we can do it submit our software then wait and see,” Spotify’s Andres Sehr tells the Evening Standard. “It’s something of a black hole.”This hints at something being whispered about in music industry circles: that Apple increasingly sees Spotify as a direct competitor to its iTunes Store, and may throw more barriers in the way of its iPhone app as a result. Describing the sometimes-cloudy approvals process as a “black hole” may be accurate, but it’s unlikely to smooth things along.Apple certainly doesn’t have a problem with streaming music apps on iPhone, as the success of Pandora and Last.fm’s apps shows. Both link through to the iTunes Store for purchases. However, Spotify’s intention to cache playlists in the app for offline listening could give Apple pause for thought, not to mention the media chatter about Spotify being a potential iTunes-killer.We’ll have to wait and see what happens once the app is submitted…