The first is a stylus with multi-touch sensors along the body, which can determine finger position and be used for gesture controls on the corresponding device.
For example, running a finger up the stylus may allow users to scroll. Or if a user rotates the stylus in their hand, a corresponding action could take place on an on-screen object. If a user grips the stylus tighter it could change the accuracy or density of the drawing on-screen. This could potentially be a feature for the next generation of the Apple Pencil, but as with all patent applications there's no guarantee this will make it into a consumer product.
Apple also filed for a patent on technology that would allow it to determine which hand a user is currently using on a device and customize the UI for left- or right-handed use. Apple can use a number of sensors to detect which hand a user is using, including the proximity sensor, accelerometer, and even Touch ID. This could help alleviate the issues people have with bigger phones like the iPhone 6S Plus. Given that Apple continues to employ its Reachability feature on the bigger phone, it's possible that it will continue to receive improvements over the coming years.