Chat on android?

Question

Android

A couple of questions:
1. What is the best way to implement the chat itself on the side of the smartphone? those. it should be a ListView with each message separately - I think the best option? or just a textview with new messages added?
2. I authorize a person on the phone through the VKontakte api - is it clear here, then I post his ID, message and token? and on the server side I check the token and id again? those. Do I make a request to VKontakte every time to match the token and ID every time I send a message in the chat?

Answer 1

1) Listview. Optional inside ImageView + TextView + TextView etc.
2) token is given for the session. Those. not every time.