Instagram is a photo and video sharing app available on Apple iOS, Android and Windows Phone. People can upload photos or videos and share them with their followers or with a select group of friends.
Pinterest is extremely visual, so if your brand is visually heavy, Pinterest is a must. If you are a fashion, food, fitness or DIY brand, Pinterest has a very large female audience.
Twitter is a social networking site that relies on micro-blogging for communication. By typing short, 280 character messages users can communicate with their followers and get information spread around.