i wouldnt say smart, but super simple and has lasted me just over 3 years. it starts to fray a little over time but i just cut off the pieces and it keeps going. Planning on getting a new one though.

https://www.amazon.com/gp/product/B00W8TU6DC/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I carry around 6-8 cards and a bill in the middle in case i need cash.