I am not using any BT 4.0 devices, but I have looked into it. I will say that you should be very careful to check any compatibility issues before you sink any money into equipment. Not all Android phones are capable of BT 4.0, and of the ones that are, it's my understanding that not all of them have the necessary coding in the OS to take full advantage. I suspect that's why items are being rolled out faster to iOS: The last two phones AFAIK have fully implemented BT 4.0. Build for iOS and a large percentage of their users are ready to go. Market to Android and there are questions about whether you phone has the physical hardware and whether it has the required bluetooth stack.

Not bike-related, but I was looking into StickNFind, and what I found was that many people seem to have bought it and/or supported the original kickstarter under the assumption that it would work with their phone, and they were upset to find out that it did not. Sometimes because they hadn't paid attention to their phone's specs, but sometimes because the phone's software hadn't been brought current. Until 4.0 becomes more standard, it doesn't surprise me that most manufacturers start with iOS.

I did look into bike-specific stuff a few months back along the lines of what you are looking for, and I also didn't come up with much luck on the Android side, so hopefully someone has a success story.