This is a life savor for me and I hope it will help you guys.
I read this once somewhere a long time ago but can't remember where so I can't take credit.
You will need to empty out a tea bag and a nail hardener or some kind of top coat.
You cut a tiny piece and measure it to your nail. Make sure it goes right up to the edge of the split. Once you have it measured put a light coat over the nail and the tea bag. Then load up top coat because it still might fall off if it's not on good.
It's as simple as that!
It's not noticeable after you put a nail polish over it.