Latest Nebo version by platform:
iPadOS & iOS: 6.2.3.17015
Windows OS: 6.1.166.0
Android OS & Chrome OS: 6.1.5.16200
Checking your Software version:
Go to Nebo help, you will see the version on the top.
iOS: Tap the 3 dots then Help 
Android:
Windows: Tap the settings icon (bottom left on the screen) then select Help
B. Do you want to know what is new on this version? What's new on this version.
C. Understanding version numbers: example: V 6.0.5.16500
The first two numbers represent the main version: 6.0
The subsequent digits denote updates or bug fixes: .5.16500
D. If you have purchased the app, you can update it through the respective app stores.
- App Store: How to manually update apps on your Apple device - Apple Support
- Google Play Store: How to update the Play Store & apps on Android - Google Play Help
- Microsoft Store: Get updates for apps and games in Microsoft Store - Microsoft Support
E. If you have a pre-installed version precedent to Nebo 6(Lenovo or Huawei devices or others) check this article: Nebo - Preinstalled versions - How to upgrade.