I use excel as it is so easy to gear it towards what you want and you can keep backdated months or years if you want to review it.

My spreadsheet is set up to track my calorie intake every day as well as an average calorie intake for the week. Off of the back of this I have a graph showing whether I am on target. I also track my weight each Sunday and have a graph linked to this to show whether my weight loss is on track.

I am a lover of spreadsheets as they are so flexible but they may not be to everyone's taste. The online tools are handy but I have never tried any. I worry that the pre loaded nutritional info may not match what you ate and I would rather check the packaging of the food I am eating.

I had a Fitbit (until I put it through the washing by mistake), so I continue to use the dedicated website. I've already programmed a lot of my foods into it (things served at Japanese restaurants, Japanese snacks, Japanese recipes), so I'm pretty tied to it right now.