Task: I would like to use the show app to add a transition effect called checkers to a presentation slide
Steps:
click on Animate button at lower left corner of the screen to add transition 
click on Animate button at lower left corner of the screen to add transition 
click on Animate button at lower left corner of the screen to add transition 
click on first option on pop up window at bottom of the screen 
choose "checkers" ( top fourth option ) from pop up window  at bottom of the screen to add transition