TigerCake is going to be some form of abstract styled first person shooter. May include some humor, so things aren't too serious.
They appear on the left arm when throwing them. The bombs will probably be the double weapon functionality, so there's not too much stuff in the view all the time.
Here's what I've thought for them...
Poison Grenade: Explodes into a cloud of poisonous acid.
Dynamite: Just has a regular good old big explosion.
Shock Bomb: Throws enemies around and stuns them.