Nintendo Letterbox, also referred to as Swap Note is due for release tomorrow, with word coming from Nintendo of Australia. Nintendo Letterbox is a free download which will give you a chance to stay connected with friends and family by swapping messages and greetings through the use of StreetPass and SpotPass technology. These letters can be a mixture of messages, drawings, photos from the 3DS Camera and even small voice recordings.
To pick this free application up, check out the Nintendo eShop through your console.