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