These are the Ukulele Chords as contributet by monkitman
(http://tabs.ultimate-guitar.com/i/israel_kamakawiwoole/somewhere_over_the_rainbow_ukulele_crd.htm)
Just re-upped them in the "chords" section to make them available in the app.

    C  Cmaj7  Am   F    G  Fadd9  Em   E7
a|--3----2----0----0----2----0----2----2------------------|
e|--0----0----0----1----3----3----3----0------------------|
c|--0----0----0----0----2----0----4----2------------------|
g|--0----0----2----2----0----2----0----1------------------|
These are the chords for just Somewhere Over the Rainbow. It does not include the
middle section of "What a Wonderful World."
Somewhere Over The Rainbow Ukulele chords. “IZ” version

Intro: 
C  Cmaj7  Am  F  
C  G  Am  F  Fadd9 F
C  Em  F  C
Oooo, oooo, oooo...
F  E7  Am  F
Oooo, oooo, oooo...
C         Em
Somewhere over the rainbow
F         C
-  Way up high
F       C
And the dreams that you dream of
G          Am      F
Once in a lullaby...
-    C        Em
Oh, somewhere over the rainbow
F             C
-  Blue birds fly
F        C
And the dreams that you dream of
G                     Am    F
Dreams really do come true...
-    C
Someday I'll wish upon a star
G                                  Am   F
Wake up where the clouds are far behind me
-     C
Where trouble melts like lemon drops
G
High above the chimney tops
-      Am           F
That's where you'll find me
-   C         Em
Oh, somewhere over the rainbow
F             C
-  Blue birds fly
F       C
And the dream that you dare to
G               Am   F
Why oh why can't I...
-    C
Someday I'll wish upon a star
G                                  Am   F
Wake up where the clouds are far behind me
-     C
Where trouble melts like lemon drops
G
High above the chimney tops
-      Am           F
That's where you'll find me
-   C         Em
Oh, somewhere over the rainbow
F          C
-  Way up high
F       C
And the dreams that you dare to
F      G         Am   F
Why oh why can't I
C  Em  F  C
Oooo, oooo, oooo…
F  E7  Am  F
Oooo, oooo, oooo…