Mobile-friendly websites
Let's try to understand what's
mobile-friendly, because it's very important nowadays for the SEO of your websites.
These problems:
Mobile viewport not set
Content wider than screen
Links too close together
Text too small to read
are something that you should notice and fix. I think it's not that difficult.
Mobile-friendly test
Google provides a good mobile-friendly test tool:
https://www.google.com/webmasters/tools/mobile-friendly/. This tool will analyze a URL and report, if the page has a
mobile-friendly design.
It was very helpful for all of my websites. Now they're much better and much mobile-friendly than before.