This is exactly the same app as the free one. If you haven't tried that one yet, please install it and take it for a spin. Afterwards, if you think it is worth 3 Euros, feel free to come back here and install this one. Given an exposure (Aperture, Shutter speed, ISO), allows calculating equivalent exposures - set 2 new parameters (a combination of Aperture, Shutter and ISO) and the 3rd parameter is automatically calculated. It is also possible to specify an ND filter of up to 30 stops, handy for those long exposure photographs to blur water and clouds. The app also includes a timer for exposures of 4 seconds or longer. Main features:aperture range from f1. 0 to f360. shutter range from 30s to 1/8000s. ISO range from ISO 25 to ISO 3. 2M. ND filter up to 30 stops, in 1, 1/2 or 1/3 stop increments. ND filter modes: stop, density, ND number. timer for exposures of 4s or longer with alarm. night mode (Lollipop and above)Permissions:control vibrator: to vibrate after the timer expires. read external storage: to enable selecting a custom ringtone stored on the SD card to be played when the timer expiresNote: in the Shutter settings section there is a switch tor camera type. This switch simply selects how a small set of shutter speeds around 1 second are displayed, choose the one your camera adheres to. Exposure calculations work for all camera makes, this switch is simply for display purposes. Please contact me if you'd like to help translating the app into your language.