WhatsApp, the $0.99 SMS-like instant messenger, is used by millions daily. In fact, the app sees a reported 17 billion messages sent across its service daily. That is more than eight times the number of messages sent on Apple's iMessage.

With its ever growing popularity, the company is looking to capitalize on its user base. Later this year WhatsApp for iPhone will move into a subscription based service where the app will cost $0.99 and the first year of service is free. Each additional year will run subscribers an additional $1 per year.

WhatsApp has been using this model on its Android app for a while now and when asked about the new subscription model, WhatsApp CEO Jan Koum said that the company just wanted "to keep things simple." He went on to say that the new subscription model "would likely follow the same pricing structure as its other apps, which are free for the first year and then cost $1/year, compared to the single, for-life $0.99 purchase that users make on iOS today."