Kanex Multi-Sync Foldable Travel Keyboard for Smartphones, Tablets

Meet the Kanex Multi-Sync Foldable Travel Keyboard: a compact Bluetooth keyboard that lets you connect and switch among 4 devices. It connects to iOS, Android, and Windows devices using Bluetooth 3.0 technology. The keyboard measures 6.42″ long and 0.51″ in thickness. Its magnets wake your keyboard when opened.

To switch devices, simply hold the function button and press Z, X, C or V. The keyboard’s 110mAh lasts for hours. Costs under $50 at this time.