Below is the declaration from Twitter about this new feature in there app:
“Retweet and Quote Tweet yourself: We’ll be enabling the Retweet button on your own Tweets, so you can easily Retweet or Quote Tweet yourself when you want to share a new reflection or feel like a really good one went unnoticed”.
HOW CAN YOU RETWEET AND QUOTE YOUR TWEETS ON TWITTER?
◾ First of all you have to locate the previous Tweet you want to Retweet.
◾ Now what you have to do is to tap on the RT button and you get these options below:
retweet shares it again. quote tweets allows you to add a new comment on top.
With the above steps you can now simply Retweet and Quote your various previous tweets. Now you can give it a shot. There are also different new features which Twitter added recently to their app, some of the improvement is on direct message limit and also the exclusion of media while counting for tweet characters.