Календарь беременности is an Android app developed by World of Secrets, designed to assist expectant mothers in tracking their pregnancy. This free lifestyle app offers several features that make it a useful tool for pregnant women. The app includes a pregnancy tracker that allows women to track their pregnancy by week or month. It also provides daily and weekly tips in the form of small, useful articles. Other features include tracking weight and belly size, calculating the current week of pregnancy and due date, counting fetal movements, tracking contractions, and maintaining a pregnancy diary with the ability to record mood, write notes, and set reminders for doctor's appointments or medication.

Overall, Календарь беременности is an excellent app for pregnant women who want to keep track of their pregnancy. It is easy to use and has a simple and intuitive interface. The only downside is that it requires an internet connection to work.