Can I attach a Bluetooth Arduino to glucometer to send information from the glucometer to the phone?
glucometer? please explain. What is your glucometer doing? What is the model?
Doesn't your phone have Bluetooth?
You can Mit App Invented 2, to make an app on an Android phone to read the info from the meter to post on your phone. The program is free to use. It's not freeware. It's an open source program made by MIT students and it's secure to use. But you need the Crome browser to use the program. And there all kinds of examples on YouTube that can help you learn to program an App.