it's an extremly boring tv show for kids.
As a matter of fact, originally it was a radio play you could buy on music cassettes. "Bibi und Tina" is a spin-off of "Bibi Blocksberg" which has been around for at least 20 years. When I was a kid (about 5 or 6 years old), the girls were listening to Bibi Blocksberg, while the boys were mainly into
Benjamin Blümchen (he's a speaking elephant...). Even today I know people my age (24 or 25) who listen to these radio plays in the evenings, if only to fall asleep more easily.
There are other famous radio plays like "Die drei ???" ("The three questionmarks") that are more mature and still very famous in Germany, especially among students of my age... I don't know if there's anything similar in other countries.