Using the Android LVL for making the application licensed and paid is clearly given. I still have doubts regarding the free trial , like if i give 30 days free trial but if user changes the date (puts a previous date on device). will it still be available for that total free 30 trial days or will it continue?
Any suggestions to handle that?
Another issue arises that if I want to give my application free of cost to some , how can that be handled if they download it from the google play / market?
There is no built-in support for trial usage in the Android LVL.
There is one way to give out paid apps for free while using the Android LVL and Google Play Store. Go to the Android Developer Console and then click Edit Profile. In the licensing and in-app billing section, enter the Google-associated email addresses of the users you want to give your app to in the "Test Accounts" section. Set the License Test Response to LICENSED. This will now allow you to send the same LVL-containing app APKs that you upload to the Google Play Store to reviewers without requiring them to purchase the app.
Two important notes on using this method:
The Google Play store does not support trials. You can implement it yourself by storing the usage start date somewhere. If you store it on the device, any user with a rooted device will be able to reset it. You can obfuscate it somewhat to make it harder. You can also store it on a server, but you need some info from the device to associate it with.
Giving apps for free is also not supported. You can develop it yourself if you have some sort of a server and use in-app purchases to enable premium features in a free app. If you want to use paid app, the only way is to actually send people the APK.
