DTMF Tone Generator is a free Android application developed by Guillaume Desbieys, falling under the category of Utilities & Tools. This application acts as a DTMF dialer for landline telephones. The app requires the user to dial the number and then press the "Dial" button. After that, users need to place their smartphone near the microphone of their landline telephone and press the "Dial" button again. In case the app doesn't work, users can plug in their earphones to their smartphone, place the earphone near the microphone, and press the "Dial" button again. Overall, the app is a convenient solution for dialing landline telephone numbers using a smartphone.