They're powerups that can activate characters special abilities, or cause a special candy to activate its power at the start of the level. The blue ball is a coloring candy which colors a random set of candies your characters color specific candy. But what is the blue wrapper thing?
The "blue wrapper thing" is to completely charge up the friend's ability at the beginning of the game. If you uses Yeti, you get a wrapped candy detonated, if you uses Tiffi then you get 2 fish, so on and so forth. The blue fish is an extra fish every time your friend is charged up. Hope that helps. Cheers