I am a great fan of Jakob Nielsen. He talks a great deal of sense about designing for all types of platform.
What is so sad is that much of what he says is good old common sense, yet it still seems beyond the ability of many designers to understand the basic principles.
Usability is important for all ages but more so for older PC/smartphone/ tablet users.
If you only have time to read one of his recommendations then it would be the following
Question from EConsultancy: What are the most common usability problems you encounter?
I’d say it’s opaque language - sites not describing things in a clear fashion. They make up their own terminology and confuse users.
It's important to use clear copy and language to help users to accomplish tasks, but some designers find it difficult to put themselves in their audience’s shoes.
Now have a look at the way you use language on your digital platforms. Easy to understand? Dick Stroud