Appointments+ -- two questions/issues

I'm desperately searching for an appointments plugin that will work for a client. I thought I had one, but then something "broke," and the developer promised to help... then just stopped responding.

My client is a nanny service, and we're selling sitters' time by the hour. So someone can book a sitter for an hour or for eight hours, based on that sitter's availability.

I'm not sure whether that's possible.

I'm also testing the plugin, and when I click a time slot, I just getting a spinning "wheel" that never stops... Help!

Thank you.