Assalamu 'alaykum wa rahmatullah,
It is established, from the sunnah of the Messenger of Allah, sallallahu 'alayhi wa salam, that at the time of breaking his fast (al-iftaar), he would say:
ذهب الظمأ وابتلت العروق وثبت الأجر إن شاء الله تعالى
Thahaba ath-Thama`, wabtallat al-'urooq, wa thabat al-ajru in shaa` Allahu ta'ala
(The thirst has gone, and the viens are rekindled, and the reward is fixed by Allah's will)
[Found in Sunan Abi Dawood, and declared hasan by al-Imaam ad-Daaraqutni, saheeh by al-Imaam al-Haakim an-Naysaboori, hasan by al-Imaam Ibn Katheer, and hasan by ash-Shaykh al-Albaani, 'alayhim rahmatullah].
Likewise, in the Sunan of Ibn Maajah, the Prophet sallallahu 'alayhi wa salam informed this ummah, that at every breaking of the fast, is a supplication that is answered.
Wa jazaakumullahu khayraa.