Osmosis is a different kind of solitaire game.
Totally free! No in-app purchases.
The objective is to promote all cards onto the board. The board has four columns, one for each suit. Cards that match the suit of the first column can be promoted at any time. You cannot promote a card to the other columns unless the card of the same rank is populated to the immediate left.
With traditional rules there are four piles of reserve cards with four cards each. Only the top card may be played. You can cycle through the deck three cards at-a-time as many times as you like.
The traditional rules don't allow for much decision making or strategy so MmpApps added a more strategic version of the game. In the strategic version rather than having reserve piles you get four empty cache spots that can hold one card each. You get two passes through the deck three cards at-a-time to win the game.
The trick is to cache the right cards at the right time to allow you to promote other cards.