You've already identified the two big questions.

After signing up and clicking around a bit, here are my thoughts:

1. Button interactions need some kind of activation effect. Whether that's a sound, or the button changes color, or something, I need to know that the button has registered my click.

2. Is there a mobile app?

3. I'm a little confused by the feed. It looks like each post also has all of the person's other posts in a slideshow. Is that accurate?