Please download the new version this correct all errors;

https://play.google.com/store/apps/details?id=com.wprograms.openwithwhats

Open in whatsapp its a free app with which you can typing to everyone people not is need saved in contacts.
This application uses the WhatsApp free API

Changes:
-Country code dropdown.
-Auto detection country code.
-Low level programming.
-Total design change.