On and off for a couple of years I've been using myfitnesspal:
https://www.myfitnesspal.com/account/login It has some features which I don't like, but it works better than any others I've tried, has several features I really do like.
I'm at a point where I need to be paying careful attention to my carb levels. I use the free app, both on my phone and on the desk computer at home, where I also print off the reports and every few days I sit and look at where I'm doing well or not-so-well, and why. I scribble notes on about what I was doing that day, which can make a big difference, I'm sure not just for me.