The search for a decent 2FA app for BlackBerry 10 is over. SAP Authenticator works perfectly on BlackBerry 10 devices. This is a generic 2FA app and is not tied to any service like Duo Mobile for BlackBerry 10. As in Android, this app requires Barcode Scanner to be installed as well. Instead of Google Authenticator you can use this. It can be used for any 2FA that uses TOTP (Time-based OTP). Happy camper!
Tip: When a website provides options for 2FA app, choose Android as the platform which will display the QR code. Choosing BlackBerry will give the secret key which we have to enter in manually in the SAP Authenticator app for setup rather than scanning a QR code.