We are familiar and well know all Swift changes between 2.0 and 2.1. And also difference between Xcode 6 and 7. But there are some changes between iOS 8 and 9.1 that we can’t ignore. Because... apps became malfunctioned.

CanOpenURL

Most significant and despicable difference is between iOS 9 and 9.1. The canOpenURL does not work as expected anymore. All checks for that are failing at this time.

if app.canOpenURL(url) {
   app.openURL(url)
}

To understand what happened, see this post: Quick Take on iOS 9 URL Scheme Changes.

But TL;DR is that you must explicitly set an array of URL schemes that your app may open. So add a key called LSApplicationQueriesSchemes to your Info.plist. And the value of this key is an array of URL schemes you want to be opened. Like: twitter, fb, instagram, vk.

More generally, xml for this in Info.plist should look like:

<key>LSApplicationQueriesSchemes</key>
<array>
    <string>twitter</string>
    <string>instagram</string>
    <string>comgooglemaps</string>
    <string>yandexnavi</string>
</array>

3D Touch

Next big thing is how to fast implement quick actions for 3D-touching app icon.

As I have no 3D Touch devices (have just Force Touch one) and have no expertise in there, I just provide a link where it described very well: Add 3D Touch quick actions tutorial.

See also:

• Is your app iOS 9 ready? — Medium.
• iOS 9 not opening URL scheme — Stack Overflow
• Quick Take on iOS 9 URL Scheme Changes
• Add 3D Touch quick actions tutorial.

Let’s code!