Hey, here is my tab for Alan Silvestri's A Promise, featured in Avengers and Iron Man 3! 
I'm surprised no one has tabbed it before...

e: --------------------------------------------------------------------|
B: --------------------------------------0---0---0---0-----------------|
G: ------0---0---0-------0---0---0-----0---0---0---0---0-0-4-2-----0---|
D: ----2---2---2---2---2---2---2---2-0-------------------------4-4-----|
A: --2---------------3-------------------------------------------------|
E: --------------------------------------------------------------------|

e: --------------------------------------------------------------------|
B: --------------------------------------------------------------------|
G: ------0---0---0-------0---0---0-------0---0---0---0-----------------|
D: ----2---2---2---2---2---2---2---2---0---0---0---0---0-0-4-2-----0---|
A: --2---------------3---------------2-------------------------4-4-----|
E: --------------------------------------------------------------------|

Then this just repeats for most of the song. Comment if you think differently! Thanks!