Android apk- do I need seperates for demo/paid?

I’ve seen some games on the android market that let you play the demo and the rest of the game is not unlocked until you buy the full version.

Can I merge the demo and full version in one APK, and if so, is there a method in Unity that allows you to check whether or not the project is paid for, or do I need to make a demo apk and a full version apk?

I’m not sure what you mean by merging two apks, but I think you’re thinking of it as two separate apps. If you want one apk, you need to think of it as one application that has two modes, in your case “demo” and “full”. You just need a setting in the game that stores if they have purchased the game or not. Something like PlayerPrefs.GetString(“DEMO”) or something that is persistent.

Then you code your game to check whether or not they have bought the full version and only let them do what you want them to do.

Maybe you could make a key app. If you buy the key, everything is unlocked. But that works only if Unity can scan your apps if there’s an app with the signature com.example.keyApp.

You can make 1 apk with App-ın purchase. Check Soomla plug-in.keywords: non-consumable item.

I used this method with my new application.You can check it from here. YOu can build the game with demo (I build with ads) , and after demo finishes you can define a AIP(app-in purchase), when I customer buys the recipe, you can check it with a query and than you save it in a PlayerPref(for offline purposes).

Good Luck, (I use Soomla because its free+well documented+dedicated developers helps you to implant , you can buy a plug-in in asset store)