NEEM

Yes. "NEEM" is in the ENABLE word list, accepted by Words With Friends and most open Scrabble apps. It scores 6 points in Scrabble and 8 points in Words With Friends.

In Scrabble, "NEEM" is worth 6 points before bonuses. In Words With Friends, it's worth 8 points. Played on a triple-word-score, the Scrabble value becomes 18.

Azadirachta indica, a large, mostly evergreen tree from India, whose seeds yield the insecticide azadirachtin.

No, "NEEM" has no anagrams in the ENABLE dictionary — it's the only word that can be formed from its exact letters.