[frankus]

I highly doubt that Bluetooth 4.0 is going to remove the biggest obstacle to these sorts of applications on the iPhone, which is Apple's review process.

Right now if your Bluetooth device corresponds to one of the handful of profiles with blanket approval from Apple (headsets, keyboards, certain accessibility hardware) you're fine, but if you're trying to do anything as exotic as serial communication with a third-party device you're shit out of luck unless you join Apple's MFI program.

And the MFI program won't even talk to you until you've lawyered up, so it's pretty alienating to anyone who wants to build something as a side project.

The same goes for serial communication. You can buy a nicely-built RedPark cable and make a stunningly beautiful app to talk to whatever device is on the other end, but your app won't make it into the store unless Apple has put the MFI stamp of approval on your device.

Since Apple controls what goes into their App Store, it would require a major shift in their approval policy before we see any significant expansion of apps that talk to arbitrary Bluetooth-enabled widgets.

(If anyone has heard of examples of approved apps using serial or bluetooth communication to talk to unapproved devices, I'd love to know!)

[kainosnoema]

I can't say much since I'm still under NDA, but I can tell you that my co-founder and I got all the way through the MFI approval process, without any kind of "lawyering up". Apple was great through the entire process—very eager to help us get our small project started.

The MFI program isn't the easiest process in the world, but it isn't impossible. Definitely doable as a side project if you're motivated.

[frankus]

That's good to hear. I remember starting to go through the signup process about a year and a half ago and by the third screen they wanted to know the contact information for my legal counsel.

I may have to revisit my project in light of your comment :)

[robspychala]

this API is it. no approval process as far as is known. the CB api treats devices no differently than web sites as far as Apple is concerned.

the reason that there are no apps yet is that only iPhone 4S has the heardware for CB and no CB chipsets out there yet in devices. chicken and egg problem which hopefully will be solved with the iPhone 4S adoption.

[davidcann]

Core Bluetooth, which is Bluetooth 4.0-only, doesn't require MFi approval from Apple, meaning it does remove the biggest obstacle.