This is a simple tool for astronomers, providing two functions. It's a combination of an astronomy light/flashlight and an astronomy calculator. First, it turns your device screen into a variable-intensity red light, to preserve your dark-adapted vision. The intensity is changed by touching the screen in different vertical positions. Second, it evaluates the telescope equations to provide resolution, magnification, surface brightness, etc., as well as recommendations for optimum viewing. There's also an embedded RPN calculator that pops up when an entry-box is clicked.
Note that your screen will stay on as long as you have this app open. Thus, you should turn off the screen when you are done in order to preserve your battery.
This application requires no permissions and is ad-free.
A good reference for the telescope equations, which I used in preparing this app, is available at
If you aren't familiar with how to use an RPN calculator, check out
keywords: astronomy, telescope, night, flashlight, light, equations, calculator, resolution, magnification