I use this code to share plain text, it works ok with SMS, and whatsapp, but when sharing text with bluetooth it sends the text as html file! the problem is I use the same sub for sharing text with most of well known applications, but it is a problem with bluetooth.
B4X:
Dim In As Intent
In.Initialize(In.ACTION_SEND, "")
In.PutExtra("android.intent.extra.TEXT", tMsg)
In.SetType("text/plain")
StartActivity(In)