Microsoft is banking on Universal Windows Apps and porting technology like Project Islandwood, the iOS to Windows 10 bridge, to help close the app gap.
In a blog post Microsoft has given a step by step demo of converting a simple iOS app, a calculator, which uses iOS Storyboards and Auto Layout, to a responsive Universal Windows App.
Windows Bridge for iOS is an open-source project that provides an Objective-C® development environment for Visual Studio and support for iOS APIs. The API coverage is still far from mature, but for a simple app like the calculator porting the app requires no special adjustment to be made to the code.
Microsoft describes the process simply as:
We are ready to run the app through the vsimporter tool. To do so, you’ll need to copy your Xcode project files to your Windows Machine (or VM). With the files copied, open the Xcode project folder on your Windows machine.
You’ll want to navigate to the directory that has the Calculator.xcodeproj folder in it. In Windows Explorer, click File-> Open Command Prompt.
Open the Windows Bridge for iOS folder (winobjc) and navigate to the “bin” folder. Find the file named vsimporter.exe and drag it onto your command prompt window, then press “Enter.”
Go back to your Xcode project folder and you will see that a new Visual Studio solution (Calculator-WinStore10.sln) has been created automatically as the output of the bridge. The Calculator app is now a Universal Windows App.
Microsoft notes their project didn’t encounter any unsupported iOS API calls, but that Microsoft is eager to help developers who do encounter such calls to help the iOS developer community to improve the bridge and enable iOS app developers to port their apps to the Universal Windows Platform.
Developers have previously noted that progress at increasing the API coverage has been slow, such as not supporting CoreAudio yet, but according to Microsoft representatives on Github Microsoft is scaling up their efforts and adding staff to address that issue.
Read more about the project at Microsoft here.