Istapaper the reader app introduced a speed reading and other features in the released update. The app highlights a single word at a time for a more focused and efficient reading. The update also brings with it faster saving of articles from mobile and Instant Sync, which is a faster and more reliable way of sending articles to your Instapaper app. After this update, the Speed Reader will be free to use ten times each month. There is also added a text-to-voice integration with Apple so that people could listen to their Instapaper articles read aloud.
Speed reading in Instapaper is based on rapid serial visual presentation (RSVP), showing you one word a time at the speed of your choosing. This method of speed reading is meant to help you eliminate subvocalization, that voice in the back of your mind repeating words as you read them, and reduce time lost scanning between words. The result is a more focused, faster reading experience.
You can enable to allow Instapaper to send you silent push notifications when you save a new article. The silent push notification allows the iOS app to download the new content from the server immediately.
Source: Instapaper Blog