DMM Talk is an Android app that allows users to make calls at half the cost of regular phone calls. By simply using the app to make calls, users can save a lot on their phone bills. It works with the user's existing phone number, so there is no need to get a new one. The app uses phone lines instead of packet communication, ensuring stable and reliable calls.

To use DMM Talk, users can download the app and register to start making calls. The app has several features, including a favorites list for frequently used contacts, a free call list for free calls within the same carrier or family, and a call history log. The app also syncs with the user's phone contacts, making it easy to find and call contacts. Users can even make anonymous calls by adding 184 before the phone number.

Note that emergency numbers like 110 and 119 cannot be dialed using the app, and users should read the terms and conditions before using the app.