Using more than one iOS/macOS device
Just like any other iOS application, a Roomie purchase is linked to your Apple ID. Your iPhone, your iPad, your child’s iPad might all have apps bound to your Apple ID and thus be able to run any app you have purchased.
The base application is free with no functionality. Subscriptions started in V7-V9 are shared via Apple Family Sharing. Subscriptions from prior versions are not shared. Unlimited subscriptions are also shared with Guests to whom you have shared a Home. Guest Sharing is provided either via an Unlimited subscription or the Unlimited Perpetual in-app purchase.
Unlimited is shared via Guest Sharing. Devices must be on same network. Your Primary Controller must be configured as documented in the Setup Guide (on charger, in foreground, optional: Guided Access active), and that Primary Controller device must own Unlimited Perpetual on the primary Apple ID signed into the device. Within 60 seconds, any Roomie Client shared to via the Sharing button in Homes or accepting the Instant Home Sharing alert and activated to the same home as the Primary Controller on the same network will have an Active subscription for that specific home. Make sure both apps on each respective device are open simultaneously.
You may use Instant Home Sharing to share the Home and the license is then shared exactly the same way to any Controller on the same network.
Purchase the in-app purchase subscription inside the V9 app in Settings > About. Guest Sharing requires an Unlimited subscription or Unlimited Perpetual.