Change product name. Adult Advantage doesnt even give the feeling it is a vocabulary software, it gives perception of different meaning

Agree with above. How about using "Language Advantage"?

The 'Adult' version could simply be called 'Advantage'.

'Lango' itself is an odd stem - whilst it is homophonic with 'language' it doesn't really evoke it. It causes me to think more of 'languid' or 'langoustine''! I know the whole brand is based around 'Lango' so there is considerable commitment to it, but 'LinguoMax' would make more sense intuitively and etymologically.

Notwithstanding the aforementioned, my lexicon is efflorescing sublimely since venturing use of this product, albeit at the sacrifice of pellucidity...