The actual workings are exactly the same. So the forcast fishing times, weather, tides etc are the same for both the Pro and Free versions.
If you are using the phone app, I am pretty sure the only difference is the Pro has no ads. As long as you use the same email address each time you will have the Pro for life even if you change phones. You can even have the App on a phone and a tablet just as long as you use the same email address.
itsaboat mate...Life is just a boat and then ya marry one !