Req advice on my apps pricing model

Hey gang,

I'm trying to think through a pricing model with my app ClipDish. Apple makes this a little challenging because it's hard to A/B test pricing plans.

Some background. ClipDish lets you clip and save recipes from the internet. When you clip a recipe from the browser, it pull out all the unwanted stuff and just saves the recipe for you.

We launched at $1.99 / month and $14.99 / year. In the initial release, the paid upgrade unlocked the app so you could save more than 6 recipes. Effectively, the app was a free-trial with a paid upgrade. We're adding new features and now we're thinking it might be time to revisit how we charge for the app.

My thoughts are around four ideas:

1. Free Trial, paid upgrade - basically, keep things the way they are. You get any of the new features that we develop but you're locked to the first 6 recipes before you have to upgrade.
2. Free version / Paid version - the free version gives you everything on one device, including unlimited recipes. Paying for the upgrade unlocks multi-device support and backups
3. Free version / pay to unlock specific features - Similar to above but rather than pay one price to unlock features you pay per feature bundle (i.e., syncing, organizing )
4. One-time purchase, unlocks all features, paid upgrades.

My question to the group is - are any of these models more appealing to you? When you've built an app, what was your thought process behind payment?