Used in celebration.
He nailed the last minute three pointer to win the game... capow!
A powerful or intense good. Instead of saying "awesome", you would say "boom good".
If someone shared that he/she has solved a challenging problem they've been troubleshooting, a friend would say "Boom good!" to express kudos and a job well done.
A high signal person is intriguing and rich in value, as in high signal to noise ratio.
When I'm at a party I always seek out the high signal people for interesting conversations.