Schedalls is an application that allows you to schedule the way you communicate, so that you’ll never forget to send that important message.Discontinued
The app seems to be no longer updated. Last version, 1.2.0, released in January 2012, can be still downloaded from the Google Play Store
RapidText is a simple SMS Scheduler and Group SMS app. It also allows you to save your SMS using labels. https://play.google.com/store/apps/details?id=com.thelabsoftware.smsscheduler.
If you are into marketing, to make money online you need a mailing list and lots of subscribers. Then to keep in touch with your mailing list you need an autoresponder system, an automated system to send out mailings and special offers automatically via email.