Frank Ritter and Kuo-Chuan “Martin” Yeh professors in Penn State’s Applied Cognitive Science Lab, have developed a free iOS app Caffeine Zone 2 that tries to help you optimize your caffeine intake. The user enters his/her weight, and then notifies the app every time he/she consumes caffeine. The app estimates how much caffeine is in the user’s blood based what was consumed when, and the user’s mass. The app can warn the user if the amount of caffeine in the user’s system rises or falls below an optimal range, an notification can by pushed to the user. Additionally, the app can warn the user if his/her caffeine density is expected to impact the user’s sleep.