SMS Backup+ Authentication Token Error Workaround

SMS Backup+ --- The Best SMS Backup Solution!

I have been using SMS Backup+ since the time I owned an Android phone.  Since SMS conversations are really important to me, I tried to find the best way to back them up.  Most apps would backup your sms by putting all your SMS data in an XML file and send it locally to your phone or to the cloud such as Google Drive.  What I like about SMS Backup+ is that it exports all your SMS conversations in Gmail like an email.  You can then search throughout your SMS conversations using the powerful search algorithm of Google!

Lately, however, the app stopped working.  The error says: XOAuth authorisation error.
In an article written by androidpolice.com, the app stopped working due to as a result of Google's Gmail API changes.  Jan Berkel, the app's developer, applied for an exemption but was denied.
Due to the loss of fuctionality, the number of stars in its review has significantly decreased.
But there is a good news after all.  There is a workaround solution to make the app work.  These are the instructions as provided by user Shackledup at github.com:

I thought it was just a corrupted Android OS that prevented it from connecting.  After a few months, I've reset my phone and still the app doesn't work.  Which led me to googling the problem that comes with the app.

SMS Backup+ Workaround

1. Turn on 2 step verification in Google Account.

2. Create an App specific password in your Google account:
Go to your Google account, select Security from the left menu, select App Passwords in the Signing in to Google box.

3. At the bottom of the list select the Select app drop down menu - SMS Backup+ won't be there, so select Other.

4. Type SMS Backup+ in the field and click generate. You'll get a 16 character password. 

5. Now open SMS Backup+.

6. In SMS Backup+ go to Advanced Settings/Custom IMAP server

7. Tap Authentication at the top and change it to Plain Text.

8. Leave the server address as imap.gmail.com:993

9. Enter your email address.

10. Enter the app password you generated WITHOUT the spaces.

11. Make sure Security is on TLS.

12. You're done, go back to the main SMS Backup+ screen and it should work.