No need of creating accounts. Just download and use. Your AppleID is your account in this app.
This app is completely free to download and use. No need to subscribe or join any trial. But there are some limits to the free version.
Paid version of this app removes all the limits and unlocks all the features of this app.
You can join the paid version by subscribing to a cancelable monthly or yearly subscription.
Your data automatically syncs across your devices via iCloud Sync.
So your data will take up your iCloud storage.