Microsoft built tools for developers to port iOS Objective-C apps with minimal modifications.

[4] Microsoft also intended for the platform to be used on ARM tablets with screens 9 inches or smaller in size, but such devices were rarely commercially released.

The platform never achieved any significant degree of popularity or market share in comparison to Android or iOS.

By 2017, Microsoft had already begun to downplay Windows 10 Mobile, having discontinued active development (beyond maintenance releases) due to a lack of user and developer interest in the platform, and focused on serving incumbent mobile operating systems as part of its software and services strategy.

[24] During the 2015 Build keynote, Microsoft announced the middleware toolkit "Islandwood", later known as Windows Bridge for iOS, which provides a toolchain that can assist developers in porting Objective-C software (primarily iOS projects) to build as Universal Windows Apps.

[25][26] An early build of Windows Bridge for iOS was released as open-source software under the MIT License on August 6, 2015.

[31] At Build, Microsoft had also announced an Android runtime environment for Windows 10 Mobile known as "Astoria", which would allow Android apps to run in an emulated environment with minimal changes, and have access to Microsoft platform APIs such as Bing Maps and Xbox Live as nearly drop-in replacements for equivalent Google Mobile Services.

Google Mobile Services and certain core APIs would not be available, and apps with "deep integration into background tasks" were said to poorly support the environment.

[32][33] On February 25, 2016, after already having delayed it in November 2015,[31][34] Microsoft announced that "Astoria" would be shelved, arguing that it was redundant to the native Windows Bridge toolkit since iOS is already a primary target for mobile app development.

The company also encouraged use of products from Xamarin (which they had acquired the previous day) for multi-platform app development using C# programming language instead.

Windows 10 Mobile also shares user interface elements with its PC counterpart, such as the updated Action Center and settings menu.

[51] The on-screen keyboard now contains a virtual pointing stick for manipulating the text editing cursor, a dedicated voice input button, and can be shifted towards the left or right of the screen to improve one-handed usability on larger devices.

[53][54] Devices can connect directly to external displays wirelessly using Miracast,[55] via USB-C, or via docking station accessories with USB ports, as well as HDMI and DisplayPort outputs.

[45][46][57] Microsoft Edge [Legacy] replaces Internet Explorer Mobile as the default web browser.

[69] Mobile builds of the Redstone branch till 14322 were halted for the device Lumia 635 (1 GB RAM) due to bugs.

Microsoft also removed statements which promoted the BLU Win JR LTE as being compatible with Windows 10.

[52][60] In February 2015, Joe Belfiore stated that Microsoft was working on support for devices with 512 MB of RAM, (such as the popular Nokia Lumia 520),[63] but these plans have since been dropped.

The build featured a Start screen, Action Center, and Continuum desktop interface that were nearly identical in functionality and appearance to their equivalents on Windows 10 for PC.

However, this iteration of the operating system was no longer backwards compatible with Windows Phone Silverlight apps.

Continuum was regarded as potentially being a signature feature over time, but that it was merely a "parlor trick" in its launch state due to a lack of support for desktop-oriented interfaces among third-party software.

[102] On October 8, 2017, Microsoft executive Joe Belfiore revealed that the company would no longer actively develop new features or hardware for Windows phones, citing its low market share, and the resultant lack of third-party software for the platform.

Microsoft had largely abandoned its mobile business, having laid off the majority of Microsoft Mobile employees in 2016,[103] sold a number of intellectual property and manufacturing assets (including, in particular, the Nokia feature phone business) to HMD Global and Foxconn (which began producing Android-based smartphones under the Nokia brand)[104] focused software efforts on providing apps and services compatible with the incumbent Android and iOS instead, and having since released dual-touchscreen Android smartphones under the Surface Duo brand.

[109] In January 2019, Microsoft announced that Windows 10 Mobile would reach end of life on December 10, 2019, after which no further security updates will be released, and online services tied to the OS (such as device backup) have begun to be phased out.