Amen : 1) Let it be!
2) Showing agreement with other's suggestion/ saying.

A word that people use at the end of their pray as a kind of "please make my wish comes true!" or in response to the father in the church when he's delivering the words of God to his children.
It can also be used in our daily conversation.

Example:
Mei - Hopefully, they will decrease the time that we have to study for English this year...we need time for other extra-curricular activities too!
Hana - Amen! It seems like I couldn't join any sport last year because of our tight timetable!