What add-ons are there?

Only what you outgrow, added from your dashboard: extra kiosks at $9 a month ($86 a year) each, extra storage at $9 a month ($86 a year) per 100 GB, an SMS number at $10 a month per business, and on Agency, extra client brands at $29 a month ($278 a year) each. Adding one is prorated, so you only pay for the rest of your billing period.