A few of these apps make T1 daily life much easier to manage! In fact, Cham and her school nurse use the Diabetes Calculator everyday at lunch when calculating her insulin dose. I'm sure there are many out there, these are just the few that we got uploaded immediately after her diagnosis.
Diabetes Personal Calculator: This app allows you to enter settings for your insulin to carb ratio for each meal, your correction factor, and your target BG. If Cham is lower than the target, it tells her how many carbs she needs to eat to return to target. If she's higher, it gives the suggested insulin adjustment to help bring her down. We love this app!!
Go Meals: This app has pretty good listings for restaurants, foods, homemade foods that you can add, and it allows you to build a meal with "Today's Plate." We use it if we forget our Calorie King book and we're out to eat.
Diabetes Buddy: This app is like a journal and we used it constantly at the beginning of her diagnosis because it has the capability to send BG levels via email. We would track her levels every time she tested and send them to the nurse if we had issues or questions about how to adjust her insulin. It has other cool features like daily activities and carbs you can enter, and it has a section to enter your medication (units of insulin) so you can remember units for each meal. This is something we are trying to get Cham to use independently so she can track her own levels and doses.