Does Android 4.4.3 support Bluetooth Low Energy in peripheral mode
According to Google I/O, peripheral mode for BLE will only be supported with Android L. (Source: https://plus.google.com/117159045047546859181/posts/79nqfUwxeZK)

Another source says it clear:


  BLE Peripheral Mode — Android devices can now function in Bluetooth Low Energy (BLE) peripheral mode. Apps can use this capability to broadcast their presence to nearby devices — for example, you can now build apps that let a device to function as a pedometer or health monitor and transmit data to another BLE device.