Duolingo is best at building vocabulary in a chosen language. After over a year in using the site to learn Spanish, I really haven't built my Spanish conversational skills very much. It is also very clear that the Duo writers tend to be very progressive and some users may be put off by the examples they use.
I collect vintage electronic items and Etsy.com is a good site to help locate them. Unfortunately, sellers can cancel a purchase after you have paid for it with little or no explanation. If a seller cancels a purchase, it is difficult if not impossible to leave any feedback on that seller. A final purchase on Etsy is not necessarily a final purchase if the seller decides they could sell a vintage item for more money somewhere else. They can refund your payment and simply say the item is no longer available.
For a sophisticated company, I am very disappointed with the design of Apple's online site for customer billing support. If you want to buy an Apple product, online navigation and help is easy, if you need help with a billing issue, it is not.
Amazon.com makes online buying very easy. It has become my go-to site whenever I intend to make an online purchase. I especially like the online reviews of products which help me in making my final selection along with pricing from multiple sellers.
I've been searching for a site offering a balanced presentation of the news; unfortunately, ABCNews.com is not it. The site has a definite left-leaning bias. Any story on President Trump is sure to present him in a negative light. It is no longer the news organization that I remember from years back.
CNN used to be my regular site for a quick update on the news; however, it is no longer useful for that purpose. I think "Baghdad Bob" must have found a new home as an adviser on news reporting at CNN. If you want one-sided, superficial news reporting, CNN is the place for you.