BT Tag Writer is an Android app developed by Sami Viitanen, available for free in the Utilities & Tools category. It provides an easy wizard that generates NFC pairing/connecting tags for your Bluetooth speakers. All you need is a modern Android phone (or tablet) with NFC functionality, and an NFC tag (NTAG203 tags recommended).

The app simplifies the pairing process for old Bluetooth speakers by generating an NFC tag that automatically connects the speaker to your device. The app requires Bluetooth permissions to enable/disable Bluetooth connectivity and scan devices for the wizard. NFC permissions are needed for writing the NFC tags. The video tutorial provides more information on how to use the app effectively.

Overall, BT Tag Writer is a useful app for those who want to easily pair their old Bluetooth speakers with their Android device.