Google Pay - Make secure payments right through your Android device.

Jasmin SMS Gateway - Jasmin is a very complete open source SMS Gateway with many enterprise-class features such as:

Stripe - Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce for online businesses of all sizes. Use Stripe’s payment platform to accept and process payments online for easy-to-use commerce solutions.

Kannel - Open Source WAP and SMS Gateway

Vodafone Wallet - Vodafone Wallet is a significantly used platform developed and published by Vodafone Inc.

Bulk SMS Services - Sending Bulk SMS to the customers will engage the customers with your business and new offers.