Online Tanker System (OTS) is a free Android application developed by Millennium Systems Consultants Pvt. Ltd. (MSCL). It falls under the category of Utilities & Tools and is compatible with Android 9.0. The app is designed to connect water tanker consumers and hydrant staff, providing an automated tanker management system.

The scarcity of water supply through pipelines has increased the dependency of consumers in major cities on water tanker services. OTS facilitates consumers to register a request for a water tanker, calculate estimated distance for transportation charges through Google maps, and forward the request to the concerned hydrant. Consumers are informed about the request through SMS, including the tanker charges, tanker driver's contact, and closure of the request.