Does my signing in with Google mean that you share my data with Google?

The short answer is no, signing in with Google does not give Google access or the right to see the contents of your entries.

Here is a slightly more detailed response...

In developing our app we choose to use Google Cloud Storage (where the data is stored) and Google Authentication (what is used to log in) to ensure that we are always using the best-in-class technology and infrastructure to protect your data.

All user-generated application data is stored in a secure, encrypted database. All sensitive data (like your journal entries) are fully encrypted before they are ever saved. In the extremely unlikely chance our database is compromised (or in the case you don't trust the privacy of Google services), the hacker (or the "eyes" of Google) would only find a nearly impossible-to-decrypt text rather than any sensitive information.

Our application is served via SSL (secure sockets layer), which means that all communication between your device and Reflection.app are also secured and encrypted.

The scary to admit, but honest truth, is no online system is impenetrable. Often the biggest risk to user privacy is a weak password. We also encourage you to enable 2-factor authentication on your Google account to further protect your account.