Bitcoin. Swish (Sweden) sees quite a lot of downtime. Why not settle for something that doesn't have these inherent issues that closed, proprietary systems have?
Apple offers the most convenient computing experience available to mankind as of right now. That's why I care, at least. I love their products and services, but not so much when it fails (as in the authors case). That shit is scary.
Love this question! Books are obviously gret. The Bitcoin blockchain looks promising as well. This is a great problem, looking forward to reading the comments. There must be some projects which tries to solve this.