Simple addon that will show the current XF version you are running in the upgrade check message.
Before:
[Image unavailable; source: https://xenforo.com/community/attachments/ucv1-png.278132/]
After:
[Image unavailable; source: https://xenforo.com/community/attachments/ucv2-png.278133/]
Before:
[Image unavailable; source: https://xenforo.com/community/attachments/ucv1-png.278132/]
After:
[Image unavailable; source: https://xenforo.com/community/attachments/ucv2-png.278133/]