How are members using computer tablets to store tabs for playing in jam sessions?

I've heard that you can use a tablet for storing your tabs rather than hauling 3 or 4 books of tabs everywhere you go to jam. I am considering purchasing a tablet for this purpose, butnone of my friendsseems to know how this works. Is an app required, or can you just take a picture of the sheet music and store it on the tablet? Is there a good way to organize them so there is easy access when a song is called during a jam sessions?