Will it fast-charge an iPhone?

Yes. It supports USB-C Power Delivery at 20W, which fast-charges iPhone 8 and later with a USB-C to Lightning cable.

Does it come with a cable?

No. The charger is sold on its own, so you need a USB-C to Lightning or USB-C to USB-C cable depending on your phone.

Only very small laptops or those that accept 20W. Most laptops need 45W or more, so it is not a good match.

It delivers the same 20W over USB-C PD but is noticeably smaller and uses GaN components.

No. It has a single USB-C port, so you charge one device at a time.

2 stores we checked sell it, including Mobilize Phone, eBay.

At Mobilize Phone, for $7.50, as of our latest check.

$7.50at Mobilize PhoneChecked 8 h ago

Compared across 2 stores. Prices are checked against each store and labelled with when.

It checks today's price at every store, compares the alternatives and answers in about a minute.