I hate monthly plans. Why bill for something I might not even use? If it's something I hate, why should I make the same hate available to you? — Buy once, use it till you exhaust the credits.
→ What is a submission?
A successful form submission where the data is sent to your email is considered a submission.
→ What after I exhaust my credits?
You'll be sent an email saying that you've exhausted your credits. You can then top-up your account with credits if you wish to do so :)
→ Will I get all features?
You will get access to every feature irrespective of the plan you are in. No feature lock-in.