SlideTimer is the way to go to perfect your Presentations.
First you enter your Presentation's Details and get a list to edit each Slide individually. After the slide-perfect editing is done you can go to the Presentation view and are ready to go. On the top right are Settings that determine when a notification should come.
Now the Time is displayed in a nice HH/MM/SS Layout throughout the App. There are also NumberPickers to edit the Duration for each Slide even better. Plus some minor changes.
SlideTimer helps you to time your presentation slide by slide. You can download it on the Play Store.