My beloved Patreon supporters make these models possible :)
This one was designed for someone having trouble with recessed buttons on a toilet due to finger disability, and provides a big paddle to push instead. It's pretty great when 3D printing can provide these kinds of easy aids to everyday life, which is why this particular model is up for free download :)
The model has a flat component that folds underneath and can be taped/glued to the cistern, and a paddle with a prong that hinges off that. The prong is angled such that it is vertical when in the raised position so that two paddles could conceivably be used, as long as the paddle ends have room to move.
Use common sense with regard to how cleanable this thing is - 3D prints are of course full of little niches for bacteria to hide. But of course, we should always consider any surface around a toilet to be contaminated anyway, and wash accordingly :P
Oh yeah, it also has a poop emoji on top :)
Note that the rounded end of the prong will move against the button, so you might want to cover the button with tape or vinyl just to keep it from getting scratched over time.