Task: I want to use show app to add the first photo from google photos to the presentation second's slide 
Steps:
click on the right arrow icon at upper left side of the screen to add new slide 
click on the plus icon ( add on) at the lower right corner of the screen 
click on the first icon ( title slide ) at the screen to view new slide
click on the plus icon ( add ) on the top of the screen to insert image 
choose media button at the bottom of the screen to insert an image 
click on the add images icon at the upper left side of the screen
choose first image at the screen from the gallery option to insert an image 
choose first image at the screen from the gallery option to insert an image