The current production versions are:
Android: 10.3.66 (April 11, 2019)
Windows: 10.3.55 (circa Dec 2018 or Jan 2019)
The Andoird version number is higher because there were some bug fix updates made (the last update was to fix a GPS epoch rollover bug that manifested in April and only affected a small number of Android devices; prior to that there were fixes for in-app purchases and some other small bugs). There should not be any feature differences.
Version 11 is currently in beta test for both Android and Windows. The most recent Windows beta release was a week ago, so it's clearly under active development.