FREE for use with an Inquisit Lab or Inquisit Web license.
An implmentation of the Arrow Flanker Task developed by Ridderinkhof et al (1997) for use with children.
Ridderinkhof, K. R., van der Molen, M. W., Band, P. H., & Bashore, T. R. (1997). Sources of interference from irrelevant information: A developmental study. Journal of Experimental Child Psychology, 65, 315–341.