How to disable calls but still receive texts Is it possible through a setting or an app to receive only text messages and not phone calls? 

Specifically I have an Samsung galaxy s3
Not sure about the Galaxy S3, but my S5 has the option to disable just the calls. Open the Dialer &rarr; Settings &rarr; Call &rarr; Call &rarr; Rejection &rarr; Auto rejection mode &rarr;All incoming calls.