Jelly SMS Lite is an app that lets you send SMS from your Mac. It lets you choose from a variety of providers you can create an account with and use it with this app. Once your account is set up and you have credits, you can start sending messages straight from this app. Jelly SMS Lite uses My-Cool-SMS as its default service and it sends you there when you choose to register for a new account. There are a few plans available ranging from 20 euros to 50 euros for the executive accounts.
Jelly SMS Lite integrates with the Address Book. This means that you can import your contacts and their numbers so you don't have to type them in every time you want to send a message.
With this new version of Jelly SMS Lite, text messages are sent in the background, so you don't have to wait for one message to finish sending to start typing the next.
The graphical user interface is very nice. It simply shows two fields. In one of them you type the number of the person you want to send a message to or select it from a list if you have imported your contacts, and in the other, you type the message.
Jelly SMS Lite can be downloaded from the App Store for free.