This script asks for OTP seed and displays OTP in a loop to support one-by-one manual migration of OTP codes.

sudo apt install qrencode

1. Export database from the app (Authenticator Plus supports Dropbox backup. Filename would be authplus.db).
2. Open the database in database reader (Authenticator Plus uses SQLite database with SQLCipher encryption - popular solution on Android. It could easily be opened using SQLiteBrowser)
3. List OTP codes. I have used this SQL statement:

SELECT email, secret FROM accounts;

4. Copy the OTP seeds one by one to the prompt from qrcodeme.sh to show QR code that could be scanned by other application. It will be displayed in terminal using ASCII art and could be scanned with mobile phone.

6. Purge database backup from disk (Linux shred or Windows SysInternals sdelete).