Yes. You can always upgrade, downgrade or cancel a subscription from My Account page on shopapper.com.
For all upgrades and downgrades, you get your account functionality adjusted instantly.
For cancellation, your apps will stop working with a notification on screen. You can modify the notification message from the Global Settings > Notification screen on your shopapper Admin Panel.
For any billing balance to occur with the plan switch, the new balance (or refund amount) will be automatically calculated based on the previous payment and billing period.