I am new in sell app to Google Play store. I have a few questions (sorry if this questions already asked)
1) when customers cancel a buy, does the apk already install will be uninstall automatically by Play store or it remains on the device?
2) does google gives customer's email account that buy the app?
Yes because you can manage the action allowed inside your app : you receive the NOT_ALLOW and are able to react directly by code. For example : when I receive the NOT_ALLOW, I immediately unable all the controls. The app gets unusable.
And you can make something more powerful : receive the NOT_ALLOW, interact with your server, do something, decide if you want to kill the app etc
The link is the Google's account. You may want to take a look at Erel's tutorial and after that, your developer console. You will find the "Licensing tests" section (sorry translated from French) where you can put the email addresses and the default action returned by GP (you can set the action manually for your tests)
You are right, I don't use any other distribution market. So perhaps do you have to search if they have their own way of tracking the licences ? Or more complex : manage it by your own. They are several ways of doing this : propose to store the user's settings on the cloud and store an ID for example or register the app for support or for a billboard, etc
I found that cached in licensing library was not to good, a licensed app could mark as an unlicensed when there is no internet connection for Google play store.
I guess you have made your tests with your own Google account (or one listed in the Licensing test section of the developer console). If it is true, you don't have to worry about. The GP cache will be filled when the customer had bought the app.
I have an app using google licensing, made by other, running on 2 devices.
On 1 device, cached works OK without internet access, on the other, the app shows unlicensed status if I block GP access to the net.
This is something developer should anticipate, there are other factors that makes licensed app marked as unlicensed.