"Boys and girls"
Translation:Gutter og jenter
AFAIK, the reason those aren't available is because of current app limitations. So nobody knows if/when those will be available on phones, which is unfortunate, because they explain quite a few things. So I'd recommend you to check them on desktop whenever you get the chance.
I would still urge you to ask questions on the forum/sentence discussions if you're ever unsure of something :)
Og is used as standard grammatical conjunction that presents non-contrasting items/ideas while pluss is primarily used in mathematics, physics, weather forecasts, during shopping sprees or as a conjunction only when you want to emphasise addition.
Seks pluss fire er ti. (Six plus four is ten.)
De har tre epler, sju appelsiner pluss ett stort jordbær. (They have three apples, seven oranges plus one big strawberry.)