The final line of this article says that it's good for families to belong to a small group or cell  in order to carry out goals of the apostolate

Some groups of families meet once a month...in each other's homes....often on a Sunday night....for a light meal, then Bible sharing, then planning of apostolic experiences

Some groups of families meet once a week ...for the same as above

The meal: everyone brings something

The sharing: adults/teenagers  in one group, children in another

The apostolic experiences: 
-  run a stall at a school/parish fete
- help with annual collection for some charity
- visit a hospital/nursing home
- visit and help poor families
- etc

Jesus, please help more families form into Christian Action Groups