The "Download Now" link directs you to the iTunes App Store, where you must continue the download process. You must have iTunes installed in order to open the link, and you must have an active iTunes account to download the application. This download may not be available in some countries.
From KeeWee Technology:
With Smart SMS you can send SMS text messages without carrier costs to other Smart SMS users, with your iPod, iPhone and iPad!Smart SMS is very simple because only needs your phone number and the phone number of your friends!Here a summary of the Smart SMS features: Up to 100 SMS text messages a day. No advertisements! Messages appears on your device as normal SMS without open the app (push notifications). No registration required: only your phone number is necessary. Contact your friends directly with your phone contact list, as for normal SMS. Does not use the phone carrier SMS service. No carrier costs. Supports emoticons!When you first run the app, you only have to choose the international prefix of your country and enter your phone number. Then, you will be able to send messages to your friends by using your existing contacts list on your phone, as for normal SMS.Smart SMS delivers messages with push notifications, so you must answer YES when the application asks your confirmation to allow Smart SMS to send push notifications.Smart SMS uses your internet connection to send SMS, so you do not have any carrier cost but only a very cheap subscription on Smart SMS::1 month: 0.79 3 months: 1.59 6 months: 2.39 The first month is FREE!Smart SMS works with any iPhone or iPod touch with at least the 3.0 OS version, and with iPad.NOTE: Smart SMS supports emoticons but it does not enable them. Emoticons keyboard must be previously enabled on your device by using other specific applications like Emoji Free! that you can download for free from the App Store.