In a way APL is 'flowchart based programming', the flow is so simple it can be used to express what otherwise would be a program with multiple constructs on a single line. Each APL character then becomes a 'box' in your flowchart. Sort of a minimalist graphical representation of what the program does.

A unix command line gives me a similar feeling with processes feeding their output into other processes each doing some kind of transformation on their input with the | character functioning as the lines in a flowchart.

Now obviously that has some differences with an actual flowchart (such as 'if' statements) but the effect is close enough that there are some parallels.