The best way to find a creative activity for kids while traveling is to give them My Travel Journal.
Which contains many interesting daily activities:

page on which the child completes information about himself (in the form of a passport)

location, date, weather, recent activities, gratitude for the day

space for doodles

everyday mood select

and many others providing great fun for kid for up to 60 days.
  It is easy to fill out and will be really entertaining for kids even on longer trips.