As I was looking for a power solution for my Boostuino project the Microchip's MCP1642 boost regulator. Finally it was not suitable for that project, but I realized this could be a good candidate for the USB Booster:
it has much higher efficiency than the good old MC34063
available locally for reasonable price
low size/value external components needed due to the high switching frequency
So based on these factors I designed a circuit for it.
The circuit is available in its newly created gihub repo: https://github.com/sufzoli/suf-electronics-USB-booster