Learning any of the Japanese alphabets can seem like a daunting task because there's just so many characters. Thing is, this doesn't have to be difficult!
The human brain works in a mysterious fashion, and everybody has their own point at which the brain commits something to memory. Katanakana watches how you identify characters, and will figure out when your brain has the best chance of storing the relations you need to read Japanese.
Once this is determined, it'll make you re-identify those characters at the ideal moment, and you'll be good to go!