You can unsubscribe via either of these methods depending on which one you used to subscribe:
Subscribe from the Exposio App
How to cancel a subscription on your iPhone, iPad, or iPod touch
1- Open the Settings app.
2- Tap on your name.
3- Choose Subscriptions
4- Tap the subscription that you want to manage.
5- Tap Cancel Subscription
Subscribe from the customer center on www.exposioapp.com
1. Log in to the Customer Center at www.exposioapp.com
2. Click on Buy credits in the left menu.
3. Click on Manage subscription.
4. Click Cancel Plan.