bonus
value-add
beneficial
gravy
supplementary
supplemental
ameliorant
enhancer
amendment
supplementation
lagniappe
egg in one's beer
could do with
improvement
banger
utility
good-good
eke out
leg
additive
icing on the cake
usefulish
bunce
something-something
dividend
corroborant
commodity
a good look
delectable
nothing to sneeze at
healthy
beneficious
gold dust
put to good use
frill
luxury
suppletory
augmentive
need-not
booster
purler
duplicate
pasella
quintessentiality
beauty
extra
every cloud has a silver lining
support
reinforcing
gooder
grist for the mill
stoater
on top of
top-up
not just a pretty face
make it count
stand in good stead
benefitable
buttress
lallapalootza
pad out
all is fish that comes to the net
exalting
buckshee
gold in them thar hills
complementer
golden goose
supplement
agreeable
goldmine
treat
emollient
gold mine
the more the merrier
addition
slice of the pie
additional
delight
crutch
adder
mixed blessing
expandable
refreshing
reinforcement
favourable
supporter
substitutable
indispensability
plus
good job
gift from the gods
continuation
solid
adjuvant
healthful
attainable
convenience
incent
sustenance
analeptic