Important: Simply deleting the app from your device won't cancel your subscription.
Apple:
Open Settings app on your iPhone or iPad.
Tap your name.
Tap Subscriptions.
Tap the Summary AI icon.
Tap Cancel Subscription.
Find more support from apple here: Apple Subscriptions Support
Google Play:
Open the Google Play Store app.
Tap on your profile icon, make sure you’re signed in to the correct Google Account.
Click on Payments & subscriptions, then on Subscriptions.
Find and open your Summary AI subscription.
Tap on Cancel Subscription.