When you upgrade to Voice In Plus, it is automatically activated in your browser. You can check if Voice In Plus is activated by going to the Voice In Settings Page chrome-extension://pjnefijmagpdjfhhkpljicbbpicelgko/settings.html
At the top right corner you should see:
This means Voice In Plus is correctly configured.
If you don't see Plus Activated, simply visit the activation page http://dictanote.co/voicein/plus/activate/
The activation page automatically detects Voice In and activates Voice In Plus in your browser. You should see on the page:
That's it! Voice In Plus is now activated!