We've seen the Spotify iPhone app in detail and it's pretty damn good

I’ve now been given an extended demo of the Spotify iPhone app which is currently awaiting Apple’s approval. Unfortunately the guy who showed it to me managed to prize the iPhone with the app on it from my cold sweaty palms, so I wasn’t allowed to take the app away on my own iPhone (alas), however, screen grabs taken from the video they released this week illustrate how the app works very well. I can confirm that everything in the Spotify app works as the video showed it. It’s in fact a very simple application, but extremely easy to use and the sound is magically good.

Here’s what I found:

The Radio feature of the desktop software is not present in the iPhone app, nor is Play Queue. Otherwise pretty much all the essential features are there.

You open up the app and see your playlists. You select a playlist and – even over 3G, not WiFi – the track streams almost immediately.

If you tap Offline Playlists and you select what you want to play when you are out of range of a 3G signal, the playlist will sync to your phone. Offline playlists need to be synced over Wifi, hence why its clear there is some kind of download happening here.

We don’t actually as yet know how they do this. There must be some kind of data download that brings in tracks which don’t appear as MP3s or as discernible tracks outside the app itself. Could the files end up being hacked out of the application? I don’t know but I daresay someone will try to find out.

Playback resumes where you left off after closing the app. While you’re playing a track you can click the “i” button and add the track or the album the track is from to your playlists.

You can also set up new playlists directly within the app. Any changes you make to playlists etc are synced with the desktop version. You can search on tracks, though not artists right now.

However, the biggest surprise is that the app works very well just over 3G. The latency between tracks is only slightly longer than over WiFi. The sound quality is, to my ears at least, excellent.

This is going to be Spotify’s killer feature – as it is on the desktop – the ability to play any track in their catalogue with no latency. Is the Spotify app the first P2P app on the iPhone? It looks like it might well be. LastFm’s iPhone app is pretty good but their latency – since the data has to stream in with no P2P software to help it – is much greater and discernible to the ear. Plus of course Last.FM is really a radio station not the proverbial celestial jukebox.

Now, it’s not clear as yet, but I am assuming I would not be able to cache vast numbers of tracks for offline playing, thus rendering my iTunes purchasing habits a thing of the past. The company has nothing to say on this but I daresay Spotify and Apple have had some pretty heavy words about this. [One commenter below suggests it’s ‘limited’ to 3,000 tracks, which would probably be way above what Apple would approve].

Lastly, co-founder Daniel Ek said something this week which makes me 99.9% sure this app will be approved for the iPhone app store: “We have a great relationship with Apple, think the iPhone is awesome and absolutely expect them to approve our app in the next few weeks. Apple has already approved several other music services such as Lastfm, Deezer and Pandora. We very much look forward to people being able to access their Spotify library wherever they might be and we’ve spent significant time and resources to ensure we’ve stuck to Apple’s developer guidelines point by point.” (Our emphasis).

In other words Spotify is betting the farm on this app being approved and they would not have done so had they not got the green light from Apple that – so long as they followed all the rules to the letter – the app would be approved.