Don’t panic this not a latest add-in for PowerPoint , but research from Denmark suggests that careful use of fonts and colours in presentations can have an effect on the audience's concentration. I first encountered this research from Ole Lauridsen, Aarhus School of Business, University of Aarhus, a few years ago and whilst sitting in a presentation where he used this research , I can tell you it works.
You can download the full document from here
Some of the great ideas it suggests are:-
We perceive colours in different orders
Red in the foreground, green and yellow in the middle and blue in the background, so put things you want remembered in red.
Our working memory processes information step by step and can never handle more than 5-9 bits of information
units at the time. Units include text, images and graphics. As a guideline 7 units is the average that we should use on a slide in presentations. Providing less than 5 information units, we are not exploiting the full the potential of the memory to a sufficient degree, and if we exceed 9 units, it becomes too much for the memory to process – thus when creating a slide you should adopt the 7±2 rule.
There are a lot more insights like this in this research and if you are looking to avoid ‘Death by PowerPoint’ this is well worth a read.