supersimple
simplistic
simplish
easy peasy
easyish
ultrasimple
forthright
plain sailing
stern
onefold
severe
stark
austere
basical
uncomplicated
nimps
downhill
eathy
mick
easy as 123
easy as ABC
simple as kiss your hand
easy as falling off a log
pimpsy
piss-easy
easy as pie
dizzy
puddysticks
straightforward
monoplex
uniplex
incomplex
like a bowl in a china shop
cut and dried
easy peasy lemon squeezy
unsimple
uncryptic
open-and-shut
unelaborate
nonsimple
unstuffy
detailless
friendly
supereasy
eath
unembroidered
unproblematic
plainful
dumbed-down
elementary