Effective if you have a wandering brain. The only downside of Flip Flip is its inability to quickly flash pictures for a long time. After a certain amount of time, it starts to hiccup. So just set longer display times for the images if they start lagging on ya. I'll post links and attachments of the basic stuff I used.
Muscle Tumblr: G-Rated Muscle (tumblr.com)
FlipFlip: GitHub link
Just to quickly go over the attached material. GIF file = seamless gif of a spiral, works nicely on 20%-40% opacity. TXT file = or script holds the words that will flash on the screen. json file = settings I use that's friendly on clunky PCs, without the spiral (you can add that separately).
Hopefully this 100% G-Rated content doesn't get flagged so I can keep it public.