(Telecompaper) BlackBerry has published an open letter to customers in major newspapers around the world to reassure them the company will continue supporting users of its smartphones. The letter outlines the measures the company is taking to improve its profitability and highlights the strengths of the BlackBerry platform, such as security, productivity and device management. The letter also confirms plans to launch BlackBerry messenger for Android and iOS devices, with around 6 million already pre-registered for the messaging service. BlackBerry did not comment on the ongoing sale process of the company. The letter concludes with an acknowledgement that 'BlackBerry is not for everyone', while stressing the bond with its users developed over the past decade. "you trust your BlackBerry to deliver the most important messages, so trust us when we deliver one of our own: Yo ucan continue to count on us," the company said.