[barrynolan]

Apple already implements a solution for free trial of apps. They're called Newsstand apps - and sadly, only available to Newsstand publishers.

Newsstand allows a free trial period. Typically it's a month.

If you like the publication enough after your trial, you can pay a monthly or annual fee. From my experience, approximately 2% of users convert to paid plans.

Download Volumes. Free trial app : upfront paid apps - 250:1. The (automated) marketing challenge becomes converting new users into paying customers.

Most paid plans for magazines are circa $4.99/month. This resembles a SaaS fee to use your app and all its wonderful upgrades.