Galaxy note 4

Samsung is planning to introduce retinal scanning tech for its future mobile gadgets, judging by a tweet send out by the company on Saturday.
The improved security was hinted within a post from the Samsung Exynos Twitter account and promised features "unique to us" accompanied by a picture showing a mobile display scanning an eye.
"Security can be improved using features unique to us. That's what we envision. What would you use?" the firm wrote, using an ExynosTomorrow hashtag.
The future now?
While the emphasis is probably on the future, the post will prompt speculation the firm may be planning to introduce the feature within the forthcoming Samsung Galaxy Note S4.
Recent rumours have suggested the phablet will boast a 5.7-inch QHD display, the new Exynos 5433 octa-core processor, 3GB RAM and a 16-megapixel camera.