In case someone installs the app, waits for the trial period to end, and uninstalls the app, I assume he will not get charged.
We want to handle scenario, if he re-installs the app that the trial period is skipped and he is charged for subscription right away.
So the question: Does Shopify provide any information for previous App installs on the same Shop, that is accessible to the App developers?
Can App developer to know if the same App has been connected to the Store before? Keep in mind we have to be complying with GDPR by deleting all data on uninstall, so we cannot store install information locally?
You seem to have answered your own question. But seriously. If you think storing a *.myshopify.com name in your own private DB is a violation of GDPR and some persons rights, I guess you're not going to be able to tell if they previously installed or not. You have no choice but to uninstall them from your App when they uninstall, meaning the re-install is always going to be fresh. So unless you keep a lookup table of those uninstalled store names, you're stuck with that. Again though, I am no lawyer but I would be very much flicking the middle finger bird at anyone anywhere that accused me of breaking some GDPR by storing a string in a DB that on its own represents nothing of importance to anyone but you. It is not a person, not a name, not an email, not an address, it is really nothing, but it is essential if you want to know previous installs.