STEPS
TOOLS
Go to your Twitter profile, click on setting button - like above - and then click settings
Then click on notifications
Click on Tweets
Turn on tweets and then nominate the twitter account you would like to add, done.
The creator of this guide has not included tools

How to use fav twitter pop up

This handy Twitter notification allows you to follow your favourite Twitter account without opening Twitter. Set this up & when your fav twitter tweets, it'll pop up on phone like a text receive