Deal: Samsung Wireless Charging Pad Slim drops to just $15 (supports iPhone X, Galaxy S9, more)4
It's very slim (hence the name) and can be used with some of Apple's products as well, such as the iPhone 8 and iPhone X. The only issue is that it doesn't come with a power brick and Type C cable, so you'll have to purchase these separately.
All in all, if you're still not convinced that it's worth owning such an accessory perhaps Samsung's current promotion will make you change your mind. The Samsung Wireless Charging Pad Slim is now 50% off, which means you'll have to pay just $15 to buy one.
On a side note, Samsung has the 10,000 mAh Fast Charge battery pack on sale as well. Each model (USB-C and Micro USB) is available for just $15.99, so you'll be saving $19 on either of the portable battery.