If you purchased your free trial or subscription from within your Studycat app on an Android device, your account is managed through your Google ID.
Please see the instructions below about how to cancel your subscription.
How to cancel a subscription on an Android device
Important: When you uninstall the app, your subscription won't cancel.
Open the Google Play app.
At the top right, tap the profile icon.
Tap Payments and subscriptions > Subscriptions.
Select the subscription that you want to cancel.
Tap Cancel subscription.
Follow the instructions.
You can access further information from Google Play: https://support.google.com/googleplay/answer/7018481