Do I need an account for online N-back?

No. You can start a round right away.

Online N-back Training | Working memory drill

N-back asks you to remember recent stimuli and decide whether the current item matches the one from n steps earlier. Many people start with 1-back.

Hold the last few items.
Stimuli appear in sequence; remember what showed up recently.
Judge the match.
If the current item matches the one from n steps earlier, respond “same”; otherwise wait.
Keep rounds short.
Finish one round, then decide whether to level up or return to real work.

Choose N-back when you want to practice updating what just happened. Schulte leans toward visual search; N-back leans toward working-memory updating.

Remember recent stimuli and decide whether the current item matches the one from n steps earlier.

No. Start immediately; accounts are optional later.