Schedule text message on iPhone Is there an iPhone app in the App Store which allows scheduling of text messages? For example, I would like to setup birthday messages, so I don't forget them, or reminder messages. I know of such apps, but they run only on jailbroken devices.

If there are none, is there any specific reason why no developer creates such an app? Android and Windows Phone have them, why not iOS?

EDIT: Apparently Apple prevents automatic sending of SMS over the SIM card (i.e. over the network carrier). But there are ways to get around this limitation without violating Apple's App Store terms.
You can use Launch Center.

It won't send the message automatically (Apple doesn't allow automatic sending of SMS), but you'll have a notification that will open a new message with the contact already selected. All you have to do is write the message and press send.