Phased Release

At WWDC 2017, Apple announced the new phased release feature of iTunes Connect. You can use it to publish an app in phases over a period of one week.

How does it work?

There is a new section called “Phased Release for Automatic Updates” on the “Prepare for submission” page of iTunes Connect:

If you are choosing the second option, the update behaviour for users who are using automatic app updates is different than normal:

After the first day the app has been published, 1% of all customers who are using automatic app updates will receive it, on the second day 2% and so on. Here’s the whole distribution:

Day 1: 1%
Day 2: 2%
Day 3: 5%
Day 4: 10%
Day 5: 20%
Day 6: 50%
Day 7: 100%

So it roughly doubles every day.

There is no difference for people who download the app or perform the app update manually though! In this cases, they will get the newest version immediately.

Since this option only applies to app updates, you can’t use it when you are submitting the very first version of your app.

Why should you use it?

So why should you use this feature? Well, it’s especially useful if you have a lot of customers. Then there are two scenarios the phased release feature can be very useful for:

1. Your app is using new web services or a completely new backend. The production environment is always a systems on its own and it’s not possible to test it in every possible way. By using the phased release feature, you can slowly increase the number of users accessing these new features.
2. Also new features inside the app can have bugs that couldn’t be found during testing. By using phased release, you can unroll these features slowly.

In the end it isn’t something that allows you to test less – instead it’s another step to ensure a higher quality of your app.

Handling problems

So you are using phased release and then you see that there is indeed a problem. In this case, you can pause the automatic update for at most 30 days. After this time, the phased release process continues. Of course you can always resume the phased release process manually.

You can use that pause to fix problems in the production system, or to submit a new app version to the app store.

In any case it’s always possible to release the app to all users at any time by using the “Release to all users” button.

Title Image: @ Baranov E / shutterstock.com