How do you know you have the latest version of Lightroom?

You're right. It does. Thanks for setting me straight. I guess if I spent a lot more time with the app I would understand it better. 

So if you launch Lightroom on the phone and click the three dots (top-right) and then choose:

Settings >> About Lightroom

You should see v 5.2.4 34BCAC

I'm using an iPhone 8. Haven't seen any update notifications for Lightroom. But I just checked the app store, and all it said was "open". So I assume everything is up-to-date. Like I said, I'm not very phone savvy.

Hi Jim you don’t say what phone you are using. On my iPhone the App store icon usually shows notifications if app updates are available – see screen grab. The present versions of Lightroom mobile are: iOS version 5.2.4 and Android version 5.2.2

Also, in the App Store / Google Store, if it doesn't say Update next to Lightroom (or Lightroom isn't in the list of Apps to update) then that should give you an indicator as to

whether you have the latest version installed Jim.

Jim, I am also a casual user. My iPhone 6 is on 13.3.1 iOS, and my Lightroom App updates automatically (now at 5.2.4).

My iPhone Lightroom has a 'cog' icon (top of screen) that opens 'settings' and an "About" page that will report the Version you have currently.

https://support.apple.com/en-au/HT202180