For your startup, what services do you use? I'm using Google Cloud storage for static assets hosting, Olark , FreshBook, Twilio , OpenVPN with private tunnel, Skype subscription, Google Voice, Sendgrid, Godaddy, Dreamhost, Prey (Preyproject), WISO Steuer (German Taxes), Hellofax ( planned)...and a couple of others.<p>What paid services or softwares do you find the most useful and critical in running your startup ?