The Android app which has gone free next as myAppFree app of the day is ND Filter Calc (DSLR). With this app yu can calculate the optimal exposure time for your pics. Just specify the filters you want to use and the exposure time of the camera and ND Filter calculates the optimum time span, for your photographs to become awesome.
ND Filter Calc (DSLR0 Features:
– Add your own custom filters
– Select one or multiple filters
– Built-in timer / alarm with optional vibration and sound
– Easy to use, simple layout
Download it today , It is FREE!!!