MEmu is a free Chinese application which runs Android in a window on your Windows desktop.
The main download is horribly slow, so we've linked to the main MEmu page, instead. This has more options, including a Google Drive download which is faster.
Once the download and setup is out of the way, life gets much easier. A window opens representing an Android tablet, a few basic apps - including ES File Explorer - and Google Play Store to help you find and add more.
A right-hand toolbar simulates shaking your virtual tablet, rotating it, adjusting volume, taking a screenshot, remapping keys or running an apk directly, while you can simulate multi-touch and tilting with the keyboard or a joystick.
The Settings dialog includes a "GPS Simulation" tab to define your location. It's set to China by default, so if you're elsewhere you should probably update it.
There are other settings to define the RAM allocated to the process, the number of CPUs, and the screen resolution (although you can run Android full-screen whenever you like).
MEmu also has shared folders for music, videos, pictures and download, making it easy to share content between Android and the host.
Add support to OpenGL ES3.1 for some new heavy graphics games, like PUBG Mobile, Black Desert, etc.
Add support to create app shortcut onto Windows desktop
Add support to apply camera to selected VM
Add support to import/export VM in batch
Improve the response speed of boss key
Fix an issue of occasional cross-hair stuck in some shooting games
Fix an issue of occasional VM deadlock when boot-up
Fix an issue of occasional synchronizer crash
Fix some other tiny bugs