Image from hughbriss.com
Twitter now lets users Pin Tweets from iOS & Android Devices.
Here is how to pin your Tweets.
1. Click on your profile.
2. Scroll down to the Tweet that you want to pin to your profile.
3. Click on the Tweet.
4. Click on the three dots on the top right hand corner of your screen.
5. Click on the drop down menu and click pin to your profile.
I have provided a link to the video provided by Twitter so you can visually see the steps.