Japanese messaging app Line on Monday announced a new and affordable alternative to landlines and mobile services. Dubbed Line Call, the service lets people make low-cost calls to landlines and mobile phones, both domestically and internationally. It's currently available to Line users with a registered phone number in eight countries including Japan, United States, Mexico, Peru, Colombia, Thailand, Philippines, and Spain.

"The ability to make calls directly to mobile and landline phones has been one of our most requested features", said Jeanie Han, Chief Executive Officer, LINE Euro-Americas Corp. While currently the service is being made available as part of Line's latest Android app, users should expect an iOS version soon, the company says.

The service offers three payment options: Call Credits, Monthly Plans, or Line Coins (for Android users only), which means that you can either subscribe or pay on the go. The call rates are quite competitive. For example, a call to any US land or mobile line costs only 2 cents per minute.

The move clearly indicates that Line, which now has close to 400 million registered users (they do not report active users), is ready to take on Skype. With Facebook-owned Whatsapp expected to release its own VoIP features in the second quarter of this year, and Viber offering a similar feature to its 300 million or so users, there is enough reason for the Microsoft-owned service to feel threatened.