Check out my demonstration video: https://www.youtube.com/watch?v=LRAIZrFhDDs
Finger Springs are a fun little game you can play with anybody with fingers! Just print off a few of these bad boys and try to shoot them into a cup! I find it works best if you print off three of them in one colour for each player. Compete with your friends! Impress your enemies! Fun for all ages!
These springs are relatively easy to print, just make sure if you're printing with a raft that the air gap is large enough that you can remove the raft easily. They should work fine with whatever your nominal settings are.
If you seek even better springiness, I suggest annealing them in a toaster oven set to around 100 C. Not only will your Finger Spring be filled with extra passion for springing, this reinvigorates worn-out springs as well! These things might be even better in ABS, but I haven't tried it. Maybe let me know in the comments!