How to create a 30 day free trial Android app? [duplicate]

This question already has answers here: Creating an Android trial application that expires after a fixed time period 开发者_如何学Python (13 answers) Closed 9 years ago.

Is there any way to receive the installation date of an Android app? Or any other suggestions on how to accomplish a 30 day free trial version?

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Just save the time when the application was first run. Then compare the time each time the program starts.

Another more secure way (the above tactic could be beaten by a simple reinstall) is to have a server of yours authenticate the imei number of the device the first time it's run and then continue the above method.

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This already has a pretty good answer:

Creating an Android trial application that expires after a fixed time period