Molecular Constructor is an Android-based free 3D modeling software for building molecules. With this application, users can design a molecule and optimize its geometry simultaneously. The app is an excellent tool for students, teachers, and researchers in the field of chemistry.

The user interface is intuitive and easy to use. The app has no ads, and it requires permission to save a screenshot only. The app is a great way to learn about molecules and their structures. The iOS version of the app is also available on the App Store.

Overall, Molecular Constructor is an excellent application for anyone who wants to learn about molecules and their structures. It is highly recommended for students, teachers, and researchers in the field of chemistry. The app is free, easy to use, and has no ads.