Gamification. "Internet points" have a way to boost one's self-esteem while not perverting as much as monetary rewards do. Even though I totally want to help for free, I'd personally like to look every now and then and see how many people I've helped over time, just to boost my feelings of self-worth.

It's also a way to establish trust between the blind and the volunteers. I haven't used the app but I imagine the blind can somehow (via voice?) specify a certain threshold of "points". Otherwise, there might be some uncool people out there doing uncool things.

The points is just a fun gamification thing. Trying to make people share and use the app.