WhatsApp, a tiny startup with a very basic idea, boring design and lots of competition, has somehow managed to connect up most of the world. And that’s actually pretty exciting. The four-year-old company — which helps users send text messages between all different types of mobile phones on all different carriers in every country – now has 300 million monthly active users, it told AllThingsD this week. That includes more than 20 million active users each in Germany, Mexico, India and Spain. WhatsApp users now send 11 billion messages and receive 20 billion messages per day (counted separately because some messages are sent to more than one recipient). That’s up from 27 billion total in June. Not to go overboard with stats, but WhatsApp has 70 percent penetration across the entire population of Brunei — not even limited to residents who have smartphones. Similarly, it has 50 percent penetration in Hong Kong.