Limit database entries for free version
<p>I'm looking to offer a free version of my app. The limitation would be that once you save 15 notes to the database, you will be limited to adding 5 notes per month. Every time you reach the limit and every time you attempt to make a new note after the limit has been reached, I will prompt the user to unlock the app via in-app purchase. 30 days after the initial limit has been reached, or the first of the month if it's easier, they'll be able to add 5 notes and I won't bother them until they use them all. The limits won't rollover.</p>

<p>Does anyone have ideas on the best way to tackle this?</p>
