Well, normally, you could assume that the Releases on GitHub might be a little newer than on various app stores because Google Play and the Apple App Stores have annoying approval processes (and optional delayed rollout strategies) but the fact that the GitHub Release is behind what they have published in the app stores is concerning...
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FYI I've got the app installed from the Google Play store, and it shows the same version as GitHub:
I don't know the answer to your question (though I'n guessing their github isn't the repo they actually use for development and thus could be a little behind), but Aurora and Google Play should have the same version, as Aurora just fetches it from Aurora as far as I know.