The motivation to program EasyFPU was to ease the calculation of Fat-Protein-Units especially for children with Type 1 Diabetes. Furthermore I was kept asking if I could provide the EasyFPU app, which is available for Android already for quite a while, for iOS. And as I've always been curious to learn a new programming language and system, here we go!
Although carbs are as well calculated, this can be done by many apps today. However, meals with a high portion of fat or protein lead to a late increase in blood glucose. Modern pump therapies can counter this by a delayed bolus. The calculation of the amount of FPUs and the corresponding absorption time is not trivial - and this is exactly what this app is doing.
The concept is simple: The user picks one or more food items from a list and enters their amount - optionally he can pick a pre-defined typical amounts. With this information the app will calculate FPUs.
Before being able to use the app, the user (or the user’s parents) need to invest a bit of time and effort to define the food items. The food list is deliberately empty when first installing the app, as every user has his own preferred food (sample data may be downloaded further down). You may limit your food list to food with a high fat or protein portion, like pizza, McDonals food, etc.
EasyFPU is available as iOS and Android app. The iOS version is the newer one with more features, as I'm using it myself as part of an insulin therapy within my family. Whether I'll ever be updating the Android version, I cannot tell - it's a spare time activity!
As an alternative to the two apps, you may use the Web version with limited features.