You can sign up/ log in in 2 ways.
1) Easiest: Use you existing Apple ID, Google ID or Microsoft ID account
2) Also Easy: Create a uses name and password in NoteDex.
Sign Up is FREE. We will not ask you for any payment details. You will be able to use the app free for 7 days, after which the app will stop working if you do not purchase. Unlike other Apple and Google apps, we don't require you start any subscription for the free trial.
Checkout this video for a quick overview of how to do both: