Hi Joanneoch,
Square's magstripe reader works with iOs and Android devices. There's two type of connectors - one for a headset jack, the other a Lightning connector. From personal past experience, the use of a dongle in between the reader and your smart device usually does not work. Perhaps others here have some additional thoughts. You may want to consider Square's Reader for contactless and chip cards as you can connect it via Bluetooth - it's been a life saver for us and you are also reducing your card acceptance liability.
jk
