You respond only to the center fish's direction and ignore the side fish, which teaches filtering out distractions and keeping attention on the main target.
Yes, on MentalMath this game is free and available without registration.
The flanking fish sometimes face the other way and mislead the child, so they learn to watch only the center one and overcome the interference.
Because it requires separating the center from the side cues, it is recommended from about age 7-8.
Yes, it works on all devices; 5 minutes a day strengthens holding attention despite distractions.