On a PC, you can use the Wudooh extension found at https://chrome.google.com/webstore/detail/wudooh/nigfaloeeeakmmgndbdcijjegolpjfhn
This will allow you to set the Arabic writing to your preferred size.
The adjective ممتاز is in fact the participle past perfect of the verb امتاز, which means 'to excel' or 'to surpass'. So, 'excellent' is probably the more literal translation, but in the end, the translation is only a step in getting a feeling for a word in a foreign language, so, I would say, any of 'excellent', 'magnificent', or in that sense also 'amazing' are fine.
- ممتازة = amazing (feminine)
- مُمتاز = amazing (masculine)
Feel free to take a look at https://duolingo.fandom.com/wiki/Arabic_Skill:Alphabet_4 :-)