system
A chat on subreddit /r/wallstreetbets
human
These rounding up an investing apps are hopeless. I downloaded my credit card statements to see how much I would have invested over a 3 month period and it was only like £20. The problem is that most transactions are at .99 so you are only investing £0.01 at the time. You will need to this 100 times just to save £1.

gpt
In america, with the exception of some podunk states, we have sales tax. This means our items marked at .99 usually end up between .05 and .20  at the register.