If the app says "Invalid email or password" and you are sure of your password, follow these steps.
1. Check the email address
Use the email you signed up with. Check for typing mistakes and spaces.
2. Reset your password
On the login page, tap Forgot Password. Enter your email and tap Send Reset Link. Open the link in the email and set a new password. Check your spam folder too.
3. No reset email after two tries?
Your account may be suspended or deleted. For your security, the screen shows the same message in every case.
Suspended: See "Why can't I log in? (account suspended)".
Deleted: Your balance and your data are kept. You can ask us to restore the account.
In both cases, email help@usenosh.com from the email address you registered with. Tell us your username.
4. You can log in, but you can't make transactions?
That is an account hold, not a login problem. See "Why can't I sell, withdraw or pay? ('User action failed')".