There have been a number of eBay promotions lately, like the site's summer sale and the recent $25 off coupon. If you missed out on those, eBay now has a 20%-off coupon code for select items. Some of the applicable categories include phones, tablets, clothes, power tools, home appliances, and more.
The 20% off coupon is valid from now until 11:59 PM PT on July 21, 2018, and maxes out at $50 off the original price. You can find items on sale by using the search box on this page. Keep in mind that the listed prices don't have the discount applied - you have to enter code PRIMO at checkout to get 20% off.
Unfortunately, there aren't very many decent deals on Android devices - the best offer I could find was an open-box LG G6 for $319.99. There are better discounts in other product categories, thankfully.