Hey Digsryan.
I have developed such type of application, either you want to pay to gateway server like twillo, or if you want a stand alone offline application using GSM Modem, with both type I have develop application, view my protfolio for ref, shareannon, and desktop base application using GSM modem for SMS alerts, let me know if you are satisfy, I have experience and can give full time to work on your project.
thanks
saeed iqbal