Task: I used the Trainline app to get a Bus from Southampton Central to London on November 3 because I had to travel there for work. 
Steps:
Open Trainline app
Click on the  from tab
Type Southampton in the from tab
Click on the destination
Type London in the destination tab
Click on the search button at the right bottom corner of the keyboard
Click on the find times and prices 
Click on the find times and prices 
Click on the bus icon