Question: Is there any way to view the stars even in a cloudy sky? For example by using a particular camera, or a particular UV filter in front of the camera, and so on.

Answer: 
Have a look at the liquid water absorption spectrum across a wide wavelength range:

[![enter image description here](https://i.stack.imgur.com/XxmcX.jpg)](https://i.stack.imgur.com/XxmcX.jpg)

As long as you are not observing from from space, there is always some water vapour along the line of sight to a star. Depending on the thickness of the cloud cover and the brightness of the stars, it may be possible to view some of the stars. 

[Relevant Wikipedia article.](https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_water)
You need an app to see the stars in a cloudy sky.