I use mySugr to record my Insulin intake and blood glucose instead of recording in a book. It's a very useful app if you don't enjoy carrying and writing in a diary.
I also have an app called SmartLog that connects to my TEE2+ meter via Bluetooth to sync my Blood Glucose onto the app straight after testing. If you have a quite up to date Glucose Meter, most have an app you can connect your phone to help track your blood glucose.
For finding and counting carbs for specific foods, I use Myfitnesspal and Carbs and Cals. Carbs and Cals is useful if you eat food from different Nationalities. As I eat mostly Carribean food most don't label their food well, but is very accurate on the app and really helpful with pictures also for portion sizes.