In many cases we have to share our phone number during purchases (online and offline) and many other cases. These numbers are shared with other third parties who sell insurance or marketing products. This will be annoying many times.
Doosra App is for you. This provides a secondary number for you which can receive SMS messages but all the calls will be directed to Voice Mail. Also there is an option to whitelist numbers from whom you need to receive calls. Also, there is an outgoing call facility also in case if you need to call them back so that your primary number is not revealed. Head over to Doosra website to read more details.