This kit is quite good value, so long as you remember not to expect salon quality products!!

The nail art pens are a great idea - combined pen and brushed varnish, completed with a de-clogging pin to clean the pen after use. The concept is simple in that the top of the brush handle can be popped off to reveal a thin metal tube, which can be used as a fine tip pen to drawn or write on the nail. It is a great idea, as it allows you to achieve a very fine line or small dots, that are difficult to freehand otherwise (unless perhaps using dotting toold, etc). The colours supplied are good too in that there is a good spectrum to cover all colour bases here although tend to stain if used on a naked nail bed.
In practice unfortunately the nail pen can be difficult to use; it is difficult to gauge the correct pressure between blobbing too much nail varnish out, and making your hand ache gripping the bottle tightly when it clogs. The tube *can* be cleaned with the pin as provided (attached to the underside of the bottles), but this still doesn't give you a truly cleaned out pen. It gets very difficult on the hands once the tube clogs, so it is definitely worth trying to keep it as clean as possible.
The brush is a thin striping brush, and so isn't suitable for coating the whole nail (it would take a long time, and result in uneven coverage). However, it is quite good at the designed use - the brushes are long and thin, perfect for lines and flicks. Yet again though, there is a slight downside that the brush quality isn't high, and they fray and splay easily. You may find yourself having to tweezer out the odd splayed fibre in order to keep the brush line clean.
All in all, these are a good low-priced entry point into nail art. If you get on with these, move onto a better quality!