Google Play app searching filter

Google Play app searching filter

I found Google Keep from the Google Play on my device. However, after
reinstalling the Android system, I can not find Google keep from the
Google Play and it shows that "Your device is not compatible with this
version"
I am very confused for this searching result while the same device ran
well with this app before.
I can understand there are several ways to install this app on my device
again.
A couple of questions confuse me..
How can I check the features that this app may change in the new version?
This may cause the reason why I can not find it in the Google Play.
Will that be any possibility to modify my device source code in order to
find this app on the Google Play in my device?
Thanks