Privacy is extremely important to the developer of this app, and thus your privacy is treated the same way. Therefore, no personal information is required to use this app. Creating an account is optional, you do not need to create an account or provide an email to use this app.
Should you decide to create an account to allow the ability to sync your watchlist from device to device, you will be asked to provide an email address to create your specific account. An email address was chosen to identify accounts for convenience of not having to remember another username, and to aid in password reset if need be.
Email addresses are currently not used for anything other than logging into the app. In the future, they may be used to notify users about app updates. If there is demand or requests from users of the app for a weekly newsletter or "Upcoming Earnings" email, then your email may be used for that purpose.
Your watchlist is also stored on the server, as well as locally on your device. Your watchlist is stored on the server as well, should you ever wish to log into the app from another device, your watchlist will sync and download to your new device.
Your email address and watchlist will never be shared with 3rd parties. No other personal data is collected, or data mined.
This app may use Google Analytics to help collect statistics regarding the usage of the app. For example, to keep track of which features of the app are used the most, in order to identify areas to focus attention and improve upon on.
All communication of the app and server HTTPS connections. Passwords are not stored on the server, they are instead hashed using industry-standard practices.