FotoTool is a free Android application that offers a collection of useful tools for both amateur and professional photographers. The app is designed to provide offline access to a wide range of features and guides to help users in different shooting situations. Besides, the app is continually updated based on user feedback and requests.

The app boasts a database of over 3800 cameras and offers parameters and values of flash, calculation of stellar traces (startrails), exposure value (EV), comparison between different exposures, calculation of long exposures, calculations for night shots and BULB mode, calculation of overall exposure, calculation of Reciprocity Failure (Schwarzschild's coefficient), calculations for Timelapses and more.

One of the most remarkable features of the app is that it has a built-in flashlight function that aids night or low light situations. It also has a stopwatch function built for photography in BULB/Manual mode and a notepad feature within the app. Additionally, the app has a connection to tutorials and help in their YouTube channel and FotoTool's blog.

In summary, FotoTool is a must-have app for photographers who need a comprehensive set of tools to help them in different shooting situations. It is free, ad-supported, and offers an ad-free version for purchase.