I agree there's no posted place that says "here's the current iFly GPS versions".
However, if you want to check whether there's a newer version on Android (which is what you asked elsewhere), just look it up in the Google Play store on the device where you have it installed: https://play.google.com/store/apps/details?id=iFly.GPS
If the green button says "Installed", you've got the latest. If it says "Update", then there's a newer version available.
If you have automatic updates enabled, then you'll get the update automatically installed within ~a day of it becoming available in the Play store, so there's not much need to pay attention to it. (I think iOS devices work similarly but I don't have experience there.)