The SMART Spelling Follow Up Online. $49 per person for 12 months of access.
Click on 'Add Another Participant' as many times as you need to buy access for multiple people and when you're done click the 'Add to Cart' red button.
If you have any trouble adding it to the cart, it may be due to an old browser (internet explorer that is now 5 years old and no longer being supported). Please try Chrome, Safari or Firefox - pretty much any other internet browser.