I noticed this yesterday. I went onto Play Store and had "10 app updates available". I then went on to Aurora Store and there were "125 app updates available".
I checked the version number of a few apps online, and it did seem as though the updates were legitimate.
My questions:
Are the updates on Aurora Store legitimate?
And, if so, why are they not showing on Play Store?
Overall, Aurora Store is an intriguing app, that completes two functions. First of all, it makes it easy to download virtually any APK offered on Google Play, and second, it enables you to manage the apps already on your device. All from an elegant, intuitive interface.
(Emphasis added)
This makes it clear that the source for Aurora is Play Store. Also the FAQ has this
Is it safe to use Aurora store?
Aurora Store is fully open-source and verified by F-Droid. If you're asking about the safety of the apps in the store, those are the exact same ones the Play Store would load and display. A lot of dangerous stuff seems to sneak past Google though, so as a rule of thumb, don't download anything which you're unsure about.
New and existing users are eligible to receive updates from staged rollouts and are chosen at random for each new release rollout.
Your app update will be available to the percentage of users in your staged rollout, but it may take time for the full group to receive the update.
Users won't be notified if they receive a version of your app in a staged rollout.
If you choose specific countries for your staged rollout, the upgrade will be limited to users with Google Play accounts in those locations.
Robert's answer gives additional reasons for staged rollouts
To summarize, you won't see all app updates available on Play Store
The updates in Aurora are legitimate Aurora store is open source hosted on Github and the latest update to readme says
The source code for Aurora Store is actively developed on GitLab. You can find the latest updates, contribute to development, and track the progress on the Aurora Store GitLab repository
Hence, there is no reason at all to doubt the authenticity of Aurora Store. As a side note the developer of Aurora store is also the developer of Warden which is a tool for privacy conscious users, since
Detects Trackers & Loggers across whole device
Allows to disable all trackers/logger
App developers usually don't publish app updates immediately to all users. Instead they publish new app versions only a small subset of users (may be 5-10%) that is increasing over time ("staged rollout").
This is a precautionary measure, because if something goes wrong e.g. an app always crashes on a certain device or on devices by a certain manufacturer then this can easily lead to a denial-of-service attack against the app support (e.g. a forum) when millions of customers trying to reach the app support.
The Aurora Store uses internally Google Play Store but using a different account. Therefore it can happen the Aurora Store account is in the group of accounts which get access to the app update earlier, therefore in this case the app update is visible earlier in Aurora Store.
