Bluetooth support is now available in KatanaMan and GT1Man, and GT1BassMan. This enables connection to the Boss device without requiring a USB connection to your phone/tablet. The connection relies on the use of a compatible MIDI/USB adapter.
The CME WIDI Uhost product has been validated for this purpose. You can find the CME Uhost here:
Details on how to set up a Bluetooth connection can be found here : How to use Bluetooth to connect to Boss Katana or GT devices