let me share my pet-project, Astrarium.
It is a free and open source desktop planetarium software for Windows.
It allows to discover night sky as seen from any point on the Earth and any date and time instant. There are many celestial objects can be observed, from eight major planets to faintest stars, asteroids and comets, deep sky objects, satellites and more; you can predict astronomical phenomenae, like phases of the Moon, planetary conjunctions and oppositions, as well as to get detailed information about object ephemerides.
Source code is available on GitHub under MIT license.
I hope it will be interesting and helpful, and I will glad to hear any comments, suggestions and opinions.
I plan to evolve the app as best I can, that's why any request from astronomy amateurs will be valueable.
If you will found any bugs, please write in this topic or, if you have a GitHub account, feel free to create an issue or feature request there.
Some screen shots are below under the spoiler.