I was surprised to play some of the 7-by-many puzzles and that "nicen" didn't seem to count. Both are listed in the Wiktionary, which I understand is the dictionary used for this game? The former word may have become accepted since I've posted this, but the latter always gives me the "Sorry, 'nicen' is not a word" message. I've not only heard it in speech for decades, but it's a pretty common verb. The usage I have read and heard express the idea of "nicen(ing) up" something (usually a room or home, but I've also seen it in the context of adjusting a person's behavior.) "Nicen up" is actually listed in the Wiktionary as the term "nicen" is derived from. Can this word be added?
Also, I cannot seem to get "pappa" accepted, despite it also being considered a noun that is a synonym for "dad, papa," etc. "Mamma" is accepted (as is Mama, if it's not the 7-by-many, so 4 letters are accepted), but I cannot seem to get "pappa" accepted. These are both common variations of the same words that simply are spelled without the double consonants in the middle.