When it comes to testing your internet speed, Ookla's Speetest.net is one of the most popular free services around. The company has had a Windows Phone 8.1 app for years, but now they look to be expanding to Windows 10.
Version 18.104.22.168 of Speedtest is now available for PC on Windows 10. Although the app is not yet ready for phone it is clear that it is designed for it as the app's layout and aspect are already mobile (interestingly, it's not adaptive meaning it cannot go bigger on PC).
The app itself is well done with clear, bold fonts, and an easy 'Go' button that tests your Ping, Download, and Upload rates along with a history of your tests. You can also easily share your results with the Windows Share Picker to push to other apps like Outlook or Twitter.
No word on when Ookla will push this for Windows 10 Mobile, but seeing as their Windows Phone 8.1 version is still kicking and there are clearly more users still on 8.1 than 10, there is probably no immediate rush.
Thanks, YC P., for the tip!