Shatter polish was a popular trend in nail polish around 2013-2014 I think, before nail art took over. I thought it looked cool, so towards the end of the trend I bought 2 shatter polishes on sale: Black and Silver.
I still wear them. The way I like to use them is to apply them to my regular polish once it starts to wear off, thereby extending the life of my nail polish. This way I can wear ordinary polish for about a week, and then get a couple of days extra wear by applying the shatter polish (silver or black depending on whether I am wearing light or dark polish) which handily covers up any chipping around the edges of the nails. I know the trend is over, but I still think it looks cool.
I bought these when they first came out, been a pretty stoic OPI customer. From memory OPI were the first polish brand to make these type of polishes, and they were very popular at the time.
Like most early adopters, I have the black shade, though it later became available in a number of colours.
It is easy to apply, but does take a bit of practice to get the shatter effect quite right. I did rock shatter effect nails for a while, but have since destashed it to my sister who has quite the OPI collection of her own.
A fun trend and unique trend to try, but one that has fallen out of favour now.