Carb manager has a free option (as does my fitness pal)
Check the values they give though as some are user entered and not checked brilliantly. Also I got confused over whether it was US total carbs or UK net carbs in many instances as it wasn’t clear. Again usually user entered figures. You can scan labels which is very helpful. And it remembers and allows you to copy and paste items or even recipes and meals or whole days so the more you use it the easier and quicker it gets.