The app is free to download and use, but requires the purchase of an auto-renewing subscription called "organization subscription" in order to create "organizations". In a typical scenario, a small business owner would download the app, buy a subscription, and create an organization, and employees would download the app and join the organization for free.
A subscription costs $6.99 USD per month and begins with a one-month free trial. After the purchase is confirmed, payments will be charged to the iTunes account used to subscribe. Note that a subscription period cannot be cancelled in the middle of its duration (lasting one month) and renews automatically, meaning it will auto-renew unless auto-renew is turned off at least 24 hours before the end of the current subscription period. This can be done by going to the user's account settings after purchase.