Reference : Hisn al-Muslim 79

اللّهـمَّ أَنْتَ رَبِّـي لا إلهَ إلاّ أَنْتَ
خَلَقْتَنـي وَأَنا عَبْـدُك 
وَأَنا عَلـى عَهْـدِكَ وَوَعْـدِكَ ما اسْتَـطَعْـت
أَعـوذُ بِكَ مِنْ شَـرِّ ما صَنَـعْت
أَبـوءُ لَـكَ بِنِعْـمَتِـكَ عَلَـيَّ
وَأَبـوءُ بِذَنْـبي فَاغْفـِرْ لي
فَإِنَّـهُ لا يَغْـفِرُ الذُّنـوبَ إِلاّ أَنْتَ
Allāhumma anta Rabbī lā ilāha illā ant, 
khalaqtanī wa anā `abduk, 
wa anā `alā `ahdika wa wa`dika mastaṭa`t, 
a`ūdhu bika min sharri mā ṣana`t, 
abū'u laka bi ni`matika `alay, 
wa abū'u bidhanbī faghfir lī 
fa'innahu lā yaghfirudh-dhunūba illā ant.


O Allah, You are my Lord, there is none worthy of worship but You. 
You created me and I am your slave. 
I keep Your covenant, and my pledge to You so far as I am able. 
I seek refuge in You from the evil of what I have done. 
I admit to Your blessings upon me, 
and I admit to my misdeeds. Forgive me, 
for there is none who may forgive sins but You.

Reference:
Whoever recites this with conviction in the evening and dies during that night shall enter Paradise, and whoever recites it with conviction in the morning and dies during that day shall enter Paradise, Al-Bukhari 7/150. 
Other reports are in An-Nasa'i and At-Tirmidhi.

Chapter: In the morning and evening