Phone Call Recorder, Spam Call Blocker, Call Filter and Caller id in a single app free app - CallMaster. CallMaster blocks spam calls and the following types of flagged calls from our database: block spam calls, block robocalls, spam likely, scam call blocker, and potential fraud calls. CallMaster also includes a Call Recorder that enables you to record all your calls easily. Key Features: ★ Spam Call Blocker ★ Easy to use call recorder - recording of incoming and outgoing calls ★ Call Filter ★