My mom recently got this app, because she is constantly on the go with my one year old sister. She figured it would be useful, especially since in January we could potentially have yet another kid with PKU in our family. My mom has been looking through the app, and she is very impressed! The information on how much phe is in the foods are VERY accurate. If I am correct there is also a way to log what you have eaten during the day on this app as well.
The only down fall my mom found was the fact that the app gives you how much phe is in one gram of the food. This is a problem for us, because we usually measure with cups, tablespoons etc, BUT it still seems very neat! I encourage you to check it out.