Note: A new more advanced BLE app in which users are able to connect to single/multiple BLE devices at the same time has been completed and is open source:
Checks if Bluetooth classic, BLE Central and peripheral modes are supported from the current device.
--> Bluetooth Classic is available in all android devices
--> BLE Central mode is available from android "Jelly Bean 4.3.x" and above
--> BLE peripheral mode is only supported from android Lollipop and above, however not all android devices that have Lollipop support the peripheral mode.
Graphics by George Alexandrou
P.S. Rating/Feedback is welcomed :-)