One (or both) of the ingenious Geekuria Youtube Channel editors (Evgeniia and Rénald) is an e-cig user. They needed a charger for an 18650 battery that they could take along on the road and charge with a USB battery. So they decided to build it themselves. This video shows how to make your own 3D printed USB battery charger.
You can get the STL on Thingiverse: https://www.thingiverse.com/thing:258… the battery holder at https://goo.gl/7MCsMT and the TP4056 at https://goo.gl/7JagVp.
We discover it, thank you for the share! 🙂