Why don't we have an "Effective App"?
See, e.g., Ribon - an app that gives you points (“ribons”) for reading positive news (e.g. “handicapped walks again thanks to exoskeleton”) sponsored by corporations; then you choose one of the TLYCS charities, and your points are converted into a donation.
Ribon is a Brazilian for-profit; they claim to donate 70% of what they receive from sponsors, but I haven’t found precise stats. It has skyrocketed this year: from their informed impact, I estimate they have donated ... (read more)
I love Momentum - to me, it's like a kind of cosmic pigouvian tax ("someone has to pay when Trump tweets, and this time it's gonna be me"); it still demands some kind of committment, though. Ribon is completely different, it's not an app that only altruistic people use; actually, that's why I didn't really like it at first, because it didn't ask people to give anything or to be effective... but then, perhaps that's why it scales well - particularly in societies without an altruistic culture. It's a low-hang... (read more)