Parts were simple and inexpensive. We already had a small free-standing shelf obtained from a garage sale, similar to the Furinno 5-tier corner shelf (Amazon, $27). Similar items can be found at Home Depot and Wayfair for under $40.
I ordered an Anker PowerPort 60 watt 6-port USB charger (Amazon, $28) and two sets of 4 ft cables - one for Android (Micro USB - Amazon, $11) and one for iOS (Lightning connector - Amazon, $22). Don't get me started on why iOS cables are 2x the cost. (Hint: Apple is evil.) 
To show how easy this project is, I tasked my 10 year-old with the build. She felt it necessary to wear a sequined cocktail dress for the photos. I stopped questioning these things a while ago. With all parts removed from their boxes she prepped the adhesive which would attach the Anker PowerPort to the shelf. I'm partial to 3M Dual Lock because it's very sticky yet removes with no residue, and it allows the pieces to be separated if needed. Unfortunately, it's also crazy expensive unless you buy it in bulk, in which case it's only kinda expensive (Amazon, $3/ft). I found that the 3M Command Adhesive strips didn't work, as the Anker PowerPort has a fingerprint-resistant coating to which the Command Adhesive won't adhere. Double-sided sticky tape might work, not sure. A bit of surface prep on the surfaces with an alcohol wipe helped.
Thoughts on the build:
- I bought 4 ft cables. I probably could have got away with 1 ft cables. Coiled cables might be better.
- I'm going to add some kind of cable organizer to keep cables tidy when not used.
