Once you've downloaded and installed HomeExchange from the App Store, it's time to log in to your account. You can currently only sign in to an existing HomeExchange.com account, you can not create a new account.
Click this app icon on your iPhone or iPad:
The App will open and offer you to sign in with your email address and password or if you use Facebook to sign in to HomeExchange.com with Facebook.
Enter your email and password in the following fields and click Sign in.