I am looking to find the most efficient way to create an application that has a 30 day trial and then forces the user to buy the full paid version if they like the demo’s features.
I was looking for suggestions as the best way to implement a license for the app. Here were some thoughts I had:
-Sharedprefs – This would work until the user uninstalled and reinstalled the app. The trial period would essentially start over.
-Use Device ID – I thought I could get a device serial number and upload the data to a server. Then I came accross http://android-developers.blogspot.com/2011/03/identifying-app-installations.html that showed the issues with trying to get a user id for a device.
UUID- It seemed like this was the best option. However, would someone be able to give me an overview of how to implement this and how it works. Also what are the limitations.
A sample implementation is already presented in the blog that you have cited.
Limitations: For your case, UUID won’t work. Since, the user can actually delete whatever file/UUID you use for tracking (not easy, but doable)
Your requirement is to track devices. So, perhaps, go for telephony ID, Mac ID or a combination of both.