As I lay out in my (not) famous weight loss book, calorie control is key to any weight loss program. To accomplish this, I am/was a big fan of MyFitnessPal. It has an easy way to log calories on my phone or the web with a good searchable database, and it used to have a magical barcode scanner. I even got my cheapo smart scale's app to sync with MyFitnessPal through Google Fit so I don't even have to type my weight anymore like some plebeian.
However, it also has some veeerrryyy question...