I had no idea what this app was for so I searched for CPD. The description under 4 of the 5 sponsored links started ‘Losses can exceed your deposits’. And this one’s ‘your capital is at risk’ is not promising either.
In the early nineties, Herb Miller led a product development project code named Silver Bullet. The team started collecting pairs of words where the first started with an S and the second with a B. This website is the continuation of that part of the project. Nowadays other projects display alternatives to their official acronyms on their websites.