In the case of the battle tower, Unique pokemon are the number of different (unique) pokemon that you have caught this season. You will know it is a unique pokemon if when you encounter it in the wild, it either has no pokeball (You have never caught one) or a pokeball with no green plus (You have caught one in a different season). A pokeball with a green plus means that you have already caught it this season, meaning it will not count towards you're points in the seasonal leaderboard. However, the only way to get unique pokemon is through catching them in the wild on your own. Hope this answered you're question!
greatEclipse's post in Help was marked as the answer
If you attached an email to your account when you created it, then you can click the "Forgot Password?" button under the log-in and it will send you an automatic email where you can reset your password.
greatEclipse's post in what are unique pokemon? was marked as the answer