Is it possible to have a free iPhone app that has say an initial 3 month ability to chat, and then after the 3 months has expired the user purchases a non-renewable subscription for additional chat time? E.G. for one month, four months, or one year? Specifically I am asking is it OK in a free app to have functionality that initially works, but after a fixed period of time no longer works unless you pay?
With Mac apps one can have a trial period. See this link. So I would think one could do the same for iPhone apps. Although in the past before InAppPurchase was available, I know this trial period behavior for iPhone apps was frowned upon.
I haven't been able to get any clarification via Google, so does anyone know if having a trial period for chat with a free iPhone app is OK or not?