This question already has an answer here:
Do you believe there should be a back button on a responsive website or should we rely on the browser's controls?
If you believe there needs to be a button in the design...
- Would you have it appear all the time or only on small (smartphone) screens?
- Do you have any examples of websites that do this well?
FYI I'm working on a website which is more a tool than a content website. Users will need to be logged in and they'll probably visit this website several times a week.
I've found this fairly recent post about the topic, and although the answer is interesting, I don't see any studies/articles to support the points that are made.
Edit: there is a similar post about this but it's nearly 7 years old so it's probably not relevant anymore