google play app distribution model?

Question

Android

I'm going to post the app on google play. I want to post a free version with limited functionality and a paid version without functional limitation. Also in the future there will be additional functionality by subscription.
What is better to lay out 1. free and paid version and then add a subscription in the paid version or 2. make one application with in-app purchases?
And then what if I release the application 3. on other platforms windows phone and ios
how to keep the subscription? to make a server with accounts?
Interested in the transition from one state to another (1,2,3) complexity, difficulties with the rules and user loyalty

Answer 1

You can do this "free and paid version and then add a subscription in the paid version", but in the free version make advertising (so that you can get money from it), some people have enough limited functionality and they will not be interested in the paid version, but built-in purchases this will be a clear minus of the application