iOS: Sending articles to your Kindle has always been a bit of a pain, but Amazon's making it a little easier for iOS users today with the addition of a Send to Kindle button in Safari.
As long as you have the Kindle app installed on your iPhone, you'll now get a Send to Kindle option in Safari's share sheet. Just tap the share button in Safari, then scroll over to the Send to Kindle option. If you don't see it, tap the More button, then flip the toggle for Send to Kindle to turn it on. This sends the article to either the Kindle app or your Kindle device if you have one. Perhaps now that you can read all those longform articles you've been saving for the last five years on your Kindle instead of in Pocket you'll actually do it.
Kindle (Free) [iTunes App Store]