This site is about iOS and Android Apps that use bluetooth to communicate with linux-based devices such as Raspberry Pi. The idea is to use to a Phone to control a Raspberry Pi, to set various parameters - such as wifi, all over bluetooth.
Currently, there is already one app iOS: BTBerryWifi.
(See it on App Store)
It uses an iPhone (iPad) to set the wifi parameters (SSID/Password) on a (headless) Raspberry Pi via Bluetooth.
An Android version is coming soon.
Please note that in order for the phone app to work, it is necessary to first install the corresponding bluetooth code (Python) and all dependencies on your Raspberry Pi (or compatible linux device). Instructions and an automated install script can be found on GitHub RPi-SetWifi-viaBluetooth.
Up to now, I have posted all information for this app on my personal blog. It is the plan to move this here in the coming months.