The blog http://glutoniana.com
is using some spanish characters (for example on a post title "Año nuevo..." where is the "ñ" char.
A friend of mine test web on its Android tabled and the "ñ" char doesn't appear (it appear a white space on its place).
This blog is using Wordpress and the template uses some Google Fonts ( 'TitilliumText22LRegular' is the font used on these titles).
How can I make the ñ character appear on all devices?
When you use Google fonts, and click on the 'Use' button, you have the option of which character sets to include (Latin, Latin Extended, Cyrillic etc.)
If the font doesn't include all possible characters, then there's nothing you can do about it.