What about Fajr and Maghrib prayers?.
The Fajr prayer (Dawn prayer) has its own Sunnah and its own remembrance, and it is the only prayer that the Prophet (PBUH) was keen to precede with two Sunnah Rak'ahs, and He (PBUH) encouraged His companions to continue praying them, as Aisha reported: "The Messenger of Allah was not so much particular about observing supererogatory Rak'ahs as in case of the two Rak'ahs of Dawn prayer" (Sahih Muslim 724), and He (PBUH) said in narration of Aisha also: "The two Rak'ahs at Dawn are better than this world and what it contains" (Sahih Muslim 725).
And Allah's Messenger (PBUH) used to recite Surat Alkafirun after Surat Alfatihah in the first Rak'ahs of the two supererogatory Rak'ahs of Fajr prayer and Surat Alikhlas in the second Rak'ahs, as Abu Hurayrah narrated: "The Prophet recited in the two supererogatory Rak'ahs of the Dawn prayer (Fajr) {Qul ya ayyuha Alkafirun: Say O disbelievers, Surat Alkakafirun}, and {Qul huwa Allahu Ahad: Say, He is Allah, who is One, Surat Alikhlas}" (Sahih Muslim 726). And as narrated by Umm Salamah: "When the Prophet (PBUH) performed Fajr prayer, while He said the Salam, He would say Allahumma inni as'aluka ilman nafi'an, wa rizqan tayyiban, wa amalan mutaqabbalan: O Allah! I ask You for beneficial knowledge, goodly provision, and acceptable deeds" (Sunan Ibn Majah 925).
As for Maghrib prayer (Sunset prayer), the Prophet (PBUH) urged His companions to perform two Rak'ahs before it, but this was optional, so that it would not become regular practice like the two Rak'ahs before Fajr prayer, as Abdullah Almuzani narrated that the Prophet (PBUH) said: "Perform prayer before Maghrib prayer, He repeated it thrice and the third time, He said whoever wants to offer it can do so, lest the people should take it as a Sunnah" (Sahih Albukhari 7368).
Therefore, some of the companions of Allah's Messenger were keen to pray two Rak'ahs between the Adhan and Iqamah of Maghrib prayer, as Anas bin Malik reported: "When the Mu'adhdhin pronounced the Adhan, some of the companions of the Prophet (PBUH) would proceed to the pillars of the mosque till the Prophet arrived and in this way, they used to pray two Rak'ahs before the Maghrib prayer, there used to be a little between the Adhan and Iqamah" (Sahih Albukhari 625). And as narrated by Marthad bin Abdullah Al-Yazani: "I went to Uqbah bin Amir Al-Juhani and said Is it not surprising that Abi Tamim offers two Rak'ahs before the Maghrib prayer?, Uqbah said we used to do so in the lifetime of Allah's Messenger (PBUH), I asked him What prevents you from offering it now?, he replied business" (Sahih Albukhari 1184).