Later in the year, following the launch of iOS 14 and iPad OS 14, Apple will allow developers to start giving out subscription offer codes in their apps.
What that means is that if a particular app has a subscription available, the developer can offer a limited-time free/discounted trial period via an 'offer code' in order to attract new subscribers, or tempt previous subscribers back in.
Each code is unique and alphanumerical and can be generated digitally, or even offline and handed out physically at various events or alongside products. That essentially means developers aren't limited in how they hand out the code and means there are a lot of opportunities to use them.
From a customer standpoint, they'll be redeemed through the App Store using a single-time-use URL, or it can be a button/option within the app itself.
There will be various options available to developers which can be passed on to potential subscribers. Developers can pass on free subscription for a limited time, or offer a pay-as-you-go trial which could be something like £1.99 per month for a limited time, with full-priced subscription kicking in later.
The third type of offer will enable a 'Pay up front' offer, where the user pays a single time for a specific duration. As an example, you could pay £4.99 upfront and gain access to six months of service.
Apple hasn't given a specific date for when the new offer codes will start appearing, but it will be at some point after iOS 14 is released to the public which expected at some point over the next couple of months.