I’ve just finished prototyping a version of FlexVolt, using the Hacker, with a Bluetooth 4.0 radio module.  There is still much work to do, but this paves the way for a FlexVolt sensor that uses Bluetooth 4.0/LE, which would make an iOS app possible!  Folks have been asking about iOS apps for a while, and the answer used to be – “No, I’m not thinking about an iOS app right now because Apple makes it hard to work with Bluetooth 2.”  Now the answer is “Coming soon!”