I used to be able to view websites like:
http://blinx.wapka.me/index.xhtml and
http://vendamp3.wapka.mobi/
on my computer screen. But in the past few months they only show up on my mobile phone screen.
Why is this, and is there any way one can make them appear again on the laptop's screen?
I am using Firefox on my laptop and my mobile phone is Android, if this is relevant.
Because the website developer has made the site show only in a mobile browser. Or rather in a browser which has sent the right User Agent string. Try to change the User Agent in your desktop browser to an Android one. If you are lucky - your desktop browser can cope with all the specifics, you will see it. You might need a Desktop Agent changer (or something like that, depends on your browser) plugin or addon.
Because they are, arguably, badly written.
For example, Google's mobile friendly guidelines explain how to create a single website that adapts itself to display well on phones, tablets and on desktops. Google have a page for testing websites
Responsive Web Design
An old-fashioned way of providing different content to phones and to desktops is to use browser-sniffing (e.g. in Javascript) to redirect visitors or to select content.
The sites you list seem to be using old versions of HTML (not HTML5) and so are probably trying to sniff browsers to determine how the site should look.
This is a bad thing to try to do. As evidence, I can view those sites using the SuperBird web browser (based on Chromium as used by Google's Chrome web-browser) on a desktop PC and see what looks like a layout optimized for smartphones. Perhaps the website's code has an inadequate small fixed list of browsers it knows what to do with.
Having sites that don't conform to Google's guidelines means those sites will be penalised in search rankings when Google search results are presented to mobile phone users. Both those sites score well in Google's mobile-friendly test, but are not "Responsive".
