I use Nutracheck, however looked at a few of the usual suspects. All just my opinion, but:
Nutracheck - 1 week free trial, then £35 for first year (when I signed up). UK specific database, really easy to use, but doesn't do micronutrient values for foods if that's important.
Chronometer - Can be used for free, £50 per year if you want premium version. Provides loads of detail on foods, down to micronutrients I'd never heard of. I found the app clunky and awkward, website is reportedly better but didn't try it.
MyFitnessPal - Can be used free, but some feature are premium only. It's £70-80 for premium. Food database is not always easy to find UK items, plus accuracy is polluted by user-added entries. That said, decent all round app and the best free option in my opinion, but expensive if you want premium features.