Mrs Mop is the Spider family with nothing held back. Two decks deal into thirteen columns of eight, every card face up, and there is no stock at all. What you can see on the first click is the entire game. That makes it the family's purest test: no card is hidden from you and no deal can rescue you, so a lost board is a board you misplayed. Eight suits have to come off, and the only tool you have is rearrangement.
An empty column is the whole game. With no stock to change anything, the only way to reorganise a board is to have somewhere to put things. Clearing a column of eight is a long project, and it is the project — everything else is preparation for it.
Think in suits before you think in ranks. The build rule will let you drop almost anything anywhere, and doing so freely is how this game is lost. Before each move, look at whether it moves a same-suit run closer to being liftable, or merely tidies a column.
Eight deep is the real difficulty. Spider starts you five or six deep; Mrs Mop starts you eight. A card at the bottom of a column has seven above it, and the only way down is to build a same-suit run under whatever is sitting there.
Nothing is hidden, so use that. Every card is visible from the first click. Take the time to find where both copies of a needed rank are before you commit — this is one of the few solitaires where the information to plan properly is genuinely all in front of you.
The Spider family is defined by a rule no other family has: you never place a card on a foundation. A run assembled in the tableau — king down to ace, all one suit — is lifted off the board whole, and collecting them all is the win. Around that sits the tension the family is really about: you may DROP a card on any suit, but you may only LIFT a run of one suit, so every convenient move builds a mixed stack you will later have to take apart. Its members differ mostly in scale: Mrs Mop is the open-information extreme: two decks, thirteen columns, everything face up and no stock. Will o' the Wisp is the opposite — one deck, seven short columns and a stock of four rows. Spider itself sits between them, hiding most of its board and dealing five rows.
Mrs Mop runs in your browser — free, no download, no sign-up. Install it as an app on your phone or computer and it works offline. You get unlimited undo, a hint button that names a legal move, statistics that track your wins and times, and seeded deals: every game has a seed you can replay, so a board you enjoyed (or lost) can be played again exactly.