Frankly - I prefer to use smartphone app to extra dongle as I have the phone witn me all the time and I don't need to carry extra gadget with me otr worry about it to be lost or damaged so if you already have phone capable of running the app I see almost zero benefit in using the dongle (note that I ave CE with dongle included but I don't actually use it for already mentioned reasons). As you can't connect more than one dongle / ap to the same service account the app is winner for me in such case.