As others have said, you can't presume that just because it's Android that it can access the Play Store. Of course you can copy over the apk and install that way but the apk for an app can be hard to find (sometimes the apk can be found on the developer's website, other times not). If you have another Android device that has the app installed, you can do a backup to an apk then copy it over to another device.
I dealt with this all the time when I had my Amazon Kindle since the Kindle didn't have access t the Play Store.
I dealt with this all the time when I had my Amazon Kindle since the Kindle didn't have access t the Play Store.