I have the Vexilar Sonarphone T-Box permanent mount model.
They have the bobber type, permanent mount and portable power supply mount.
It is WiFi not Bluetooth.
I have the App on some smartphones and tablets. There is an iOS app and an Android app for the Sonarphone.
You can download the FREE app to see the Simulator.
This is both versions in the original configuration. The white device is an iPad:
The iOS version was recently changed to the Android configuration:
Coupled with Navionics mapping, you can do Sonar Charts Live and create HD contour mapping for any location.