If you need to get someone's attention, it is best to add the before their name. That way they will be alerted to your message.
Not sure what you mean by an example? If you mean an example of when you'd need to have an internet connection, see above.
As mentioned you would need an internet connection if a user wanted to make an IAP (In App Purchase), or if you wanted to display ads in your app.
For anything further, you can just make a simple game yourself. Then export to cocoonjs, and run on your phone!