Facebook Inc.’s WhatsApp messenger service is going to be free, but may come at the cost of outside businesses having more access to users. Previously, WhatsApp users paid $1 annually after one year of using the messaging app. The company got rid of the $1 fee, but said it would begin to test tools this year to allow outside businesses to message users. In a blog post, the company said these tools will allow communications with organizations “you want to hear from.” “That could mean communicating with your bank about whether a recent transaction was fraudulent, or with an airline about a delayed flight. We all get these messages elsewhere today—through text messages and phone calls—so we want to test new tools to make this easier to do on WhatsApp, while still giving you an experience without third-party ads and spam,” the company wrote in a blog post. WhatsApp said the company doesn't have specific outside partners lined up yet, but that more details will come later this yea