To calculate the correct exposure equivalence based on an initial shutter speed, aperture and ISO settings.
You can use the calculator with ND filter. Determine how to make 1000 times longer photos, for example.
Two of the three parameters can be blocked, the last parameter is determined automatically.
The minimum and maximum speed can be set, it goes the same for aperture and ISO to be specific to your device.

Free version sponsored by some ads. If you want to support the development and use an ad-free version install
https://play.google.com/store/apps/details?id=com.ccl.longexposurecalculator.noad

Keywords:
photo, ND filter, long exposure, exposure calculator

Performance improvement
Advanced settings that allow you to configure all speeds, apertures and sensitivities manually.

// Option A //

To download Exposure calculator mod from HappyMod.com.
You need enable the option "Unknown Sources".
1. Click on the above link to download Exposure calculator mod APK.
2. Save the file in your device Downloads folder.
3. Now tap on Install and wait for the installation to finish.
4. Once it is done, open the game and start playing it right away.

// Option B //

To download Exposure calculator from HappyMod APP, you can follow this:
1. Open your browser and download the HappyMod APK file from HappyMod.com - the only official website of HappyMod.
2. Open Android Settings and go into Privacy or Security.
3. Tap the option to Allow Unknown Sources and enable it.
4. Go to your Android downloads and tap the APK file.
5. Follow the directions on the screen to install it.
6. Search Exposure calculator in HappyMod App.