Absolutely! You can use it for whatever you want, as long as you credit it. What monetization model do you think would work better?
I'd say either a one off ($5 for an idea, some amount of time like 30 or 90 days max) pricing, or if you do subscription then consider an annual (that way you don't pay the $0.30 credit card processing fee every month, just the 2.7%) but very cheap plan like $20/year, or maybe even a lifetime option (I don't know, $80?)
I just think that the monthly subscription is not necessarily aligned with the lumpy usage pattern most users will have and therefore you risk a lot of churn when people haven't had a new idea in 3 months and wonder why they're still paying every month