I Rake in Rewards with the System

After opening a golden finger shop, Ye Xu finally had a way to protect himself.

In famine-stricken times, he has his grandfather bind a sign-in System. In the imperial palace, he has his mother bind a palace-intrigue System. In a backward era, he has his siblings bind a study System. When the apocalypse arrives, he has his whole family bind a monster-slaying, level-up System...

Ye Xu: "Nothing is more satisfying than taking advantage of the shop."

*Most likely a slow-paced transmigration story. The protagonist moonlights as customer support for the Systems.

Two other books in the same series, featuring the same protagonist:

Completed: I Sell Delicious Food Through Card Draws, a story about running and upgrading a food shop

Completed: I Derail the Plot by Selling Medicine, a look at magical potions wreaking havoc across various planes

Theme: Striving for the whole family's happiness.