Sometimes I see the verb tense 'ap' is placed between verbs. For example 'Konsa moun yo vin ap viv ak matyè e fatra sa yo'. Can you explain this further and give examples on how to use it?

Yes.  The first verb becomes a helping verb. The first verb may be in the present , past, future tense.
The second verb is usually in the continuous form.

1. Li te kontinye ap aniye m.
    She kept bugging me

2. Mwen te vin ap panse avè l. (I came to think about her)
    I started thinking about her.

3. Mwen te tonbe ap rele, "Anmwey! Osekou!"
    I started screaming, "Help! Help!"

4. Li te rete la ap kriye devan sèkèy la.
    She stayed there crying in front of the coffin.

5. Yo te kanpe ap gade tout sa ki t'ap pase.
     They stood watching everything that was going on.

6. Fanm nan pral koumanse ap joure  si nou pa ba li kafe li.
    The woman will start cursing if we don't give her her coffee. .

7. Chak jou yo te kontinye ap rale cheve l, ap joure'l, ap takinen'l, ap bat li, jouk li te defann tèt li.
    Everyday they kept on pulling her hair, cursing her out, teasing her, beat her until she fought back.

Haitian Creole ↔ English Reference, Look up Haitian Creole and English Words