Data you enter in the app is stored securely in a Firebase database.
We show a couple of banner ads using Google AdMob to keep the app free (or you can subscribe to the premium or ad-free versions).
Members of the European Economic Area (EEA) have the option of selecting personalized or generic ads.
What does this mean? Jane Smith has an Android phone and uses her Google account to log in to the Play Store and download this app. To show personalized ads we would ask AdMob "send us a banner ad for the current user (Jane Smith)" and AdMob would use whatever information Google has about Jane Smith to send an ad. For a generic ad we would ask AdMob "send a generic banner ad".
There are ads either way, and they will likely be more interesting to you if you choose the personalized option.