Space Engine - Space Engine is a realistic virtual Universe you can explore on your computer.
Cast Your Vote - Cast Your Vote is an app that allows you to set polls and a voting system and know the answer to your question.
Celestia - Real-time 3D visualization of space
Pollie - Create polls and share them via your favourite tools
Stellarium - Stellarium is a free open source planetarium for your computer.
Right2Vote - Right2Vote is an e-voting app that lets you create and manage polls or election campaigns.