Safety of "Apple"-branded iPhone chargers listed on Amazon vs. MFi-Certified alternatives
Apple Products

If you ever think of purchasing Apple branded products, your only safe place to make your purchases are Apple Stores or the Online Apple Store. If you prefer to make fast and safe purchases online, you can download the Apple Store App by Apple and make purchases there.

MFI Certified Products

When purchasing these non-Apple branded products you must pay attention. 
If they're certified by Apple, you just need to find a brand you trust and make your purchases safely while saving some money as well!
I've purchased one MFi certified cable for my iPhone 6s as a second option, and I've encountered no issues so far. Then, yesterday, a friend of mine tried it as she needed to charge her iPhone 5s, and she had no problems at all either! MFi cables are a great bet. Some of the best and most reliable cables sold on Amazon are made by AmazonBasics and Anker (Anker makes a power adapter brick too).



In the end, you should always buy cables you are certain are genuine, because counterfeits are downright dangerous. If you need to purchase from Amazon, buy a high-rated MFi cable from the likes of AmazonBasics, Anker, or Sync-Wire. Otherwise, purchase a genuine Apple charger straight from the Apple Store. I would totally suggest you to try the Amazon route: you'll save a few dollars and you can easily get a refund if the cable goes bad quickly. And if you purchase a cable that's "genuine" and "made by Apple", you must buy it through the Apple Store.

If you're interested on the brand of the cable I bought (made by Sync-Wire), here's the link to the product, and you may find interesting to browse their website if you're curious about their products!