I use an iPhone and I use "Diabetes App - Blood Sugar Control". You can put in your medication. Your weight, blood pressure, blood glucose, and it has a food diary, counts net carbs, carbs, fat, protein. It has pre set foods, but you can add your own as well. You can create "recipes" where you can add the individual ingredients of something home made. You can put in blood sugar targets. It will create on screen graphs, so you can see how your doing, over a week or period such as lunchtime. It will also create a spreadsheet which you can email to yourself or your doctor. I got the "Lite" version at first which is free and works for about 3 weeks of info. I bought the app after that (it was either £2.99 or £4.99), but it's a one off payment and I think it's well worth the money. I've tried carbs and cals & also My Fitness Pal, but I think the Diabetes app is far superior, to anything else out there. It's produced by B.H.I Technologies
I've only recently got a meter so just started logging . I'm on Android and use Diabetes M as recommended by someone here (sorry can't find thread to acknowledge)
It allows me to log everything I currently need (T2), and shows past data in charts and graphs which are all exportable. I'm enjoying using it, just wish my readings would fall .....