From Medma Infomatix:
Application Features. Reject calls from listed numbers in the blacklist group. Rejects calls with automatic SMS reply which could be customized by the user. Allows users to make a white-list of contacts whose calls would only be allowed over the phone. Application could be configured to reject calls for a particular time duration. Application runs as a background service over the Android Platform and could be enabled and disabled anytime. Listing of contacts in black list and white list could be done from saved Phone contacts. Listing of contacts in black list and white list could be done by manually adding any unsaved number as well. Application is free and requires no registration. Application users are provided with e-mail support. Application supports Android OS V2.1 or higher.