This service has solved many of my problems and I am completely satisfied with it. I would like to say that I have not little experience with other similar services, but I think this is one of the best.
Good software for sending SMS to clients. As for the price it's quite cheep in compare with other companies.
Jasmin SMS Gateway - Jasmin is a very complete open source SMS Gateway with many enterprise-class features such as:
ProTexting - ProTexting offers mobile marketing tools for businesses to communicate with their audience via SMS & MMS campaigns.
KAPSYSTEM - KAP Computer Solutions Pvt. Ltd.,
ShoutOUT - All in one business texting tool to send personalized alerts, promotions, reminders, short links and marketing campaigns, for any SMEs (hotels, restaurants, education, non profits, Woocommerce, banks, healthcare, agencies, supermarkets, weddings)
Textmagic - The all-in-one solution for all your business texting needs - marketing campaigns, two-way SMS chats, reminders, notifications, and internal staff communication.
Clickatell - Simple, reliable mobile messaging cloud.