I see that bluefruit le is supported but I want to check if Bluefruit UART friend is supported as well? Is there any issues with the BLE widget? in my Android phone the BLE widget is not activated. I can’t install it. However, my Iphone has it activated. I am kind of confused because it is supposed to be good with the Android but not with the IOS yet. please let me know.
From my testing, you need to have a BLE device and/or Bluetooth communication picked in the App, in order to have the BLE or BT widgets available (try Generic Board and BLE connection). Also, it currently seems that Bluetooth and BLE is limited to the App ↔ MCU device connection link via Blynk.begin(SerialBLE, ...) and not usable outside of that hidden layer. Your Adafruit Bluefruit LE UART Friend seems a bit more than a simple BLE module, so it may not play nicely in this roal? Just a guess.
Your iPhone probably shows it available because newer iPhones seem to have have inherent BLE built in… yep, another guess 
But that doesn’t mean it will actually work for Blynk, yet.
All around, it is a bit confusing at first. I think the developers are working on something more down the road.
@Gunner Thank you for the quick response. When I try to connect from iphone, i can choose the bluefruit device and then it say fail to connect. I think even if it works, it will not be reliable.