In Bunker games you try to get all the cards onto the tableau which builds in mixed suit. All four versions are free-to-play, no in-app purchases.
Bunker can be played with an incomplete deck, although we always play with a full deck. Supposedly it got its name because soldiers in bunkers often had incomplete decks of cards so they would play this game.
Bunker - No cache spots.
Bunker 2 - Two cache spots.
Bunker 4 - Four cache spots.