Spotbros, which launched internationally last month on Android and iOS, served more than 130,000 downloads in its first week and now has more than 300,000 users, primarily in Spanish speaking countries.

The app builds on a foundation of basic messaging and then layers on a host of features. There’s an option to send location-based messages called “shout” to the first 50 users inside of a mile. A shout can passed along to other users through a “re-shout”. Users can also set up their own permanent chat group called a “spot” that is tied to a place, so a neighborhood or activity group can set up an easy way to communicate. Users can join a spot or create their own.

The messages themselves have an extra layer of complexity. SBMails are actually separated into two parts — a basic message with 200 characters, which is connected to a microweb page that can hold a title, videos, images, text and maps. People who receive the message can comment, contribute to a larger thread or share the page through its own URL. 

Spotbros is designed to be secure, so it encodes messages with AES 256-bit encryption. Users must approve who is able to send them direct messages and they can filter out shouts they don’t want to receive. All of the messages get erased from Spotbros servers within 30 days unless someone chooses to save a thread.

The app faces a tall challenge in taking on WhatsApp and becoming a major player in the messaging wars. And it needs to find a way to make location-based sharing compelling for users. The space hasn’t been kind to many startups, including Yobongo and Color. And many location-based people discovery services have also struggled to gain a big following.

But co-founder Alejandro Lopez Monge believes there’s an opportunity to create a safer, more flexible messaging service that builds off the ease of instant messaging.

“We believe that instant messaging can be the glue that will keep together users, online content and location based services. We see IM as a means, not an end,” said Lopez Monge.

Lopez Monge, a foreign exchange trader at HSBC, launched the company with Fernando Calvo, a former Accenture strategy consultant, earlier this year and the two raised $500,000 from Spanish investors and Kallasvuo, who Lopez Monge met at HSBC. While the app doesn’t have any monetization features yet, Lopez Monge said they are looking at location-based offers from local merchants.

While Spotbros is finding adoption in places like Spain and Latin America, I’ll be curious to see how it can compete in the U.S. We’re still waiting to see if people want to really communicate with strangers nearby. But as we’re noticing with the growth of NextDoor, a social network for neighborhoods, there’s more interest in being connected to a group of people nearby. I can imagine that would be where Spotbros finds success, if it can be a mobile way for neighbors and like-minded people to communicate.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• Facebook’s tactical retreat on privacy
• Google and the Ghost of Silicon Valley Past
• NewNet Market Overview, Q1 2010