I don't tend to go far, and rarely use a routefinder. We are going away at Bank Holiday and dreading traffic problems! We would normally use an offline journey planner which has been downloaded onto a tablet, which uses GPS. So we'll use that to find our way. The tablet doesn't have access mobile data, however.
I do have a mobile phone I can use to check traffic. It's an older one without space for many apps, so I'd rather just look on a website rather than installing something.
Which website do you like?