ND Stack Timer is an offline long-exposure calculator for photographers who combine neutral-density filters in the field. Use it to: - add up to three ND filter stop values - convert a base shutter speed into a corrected exposure - see the factor added by the stacked filters - round the exposure for a practical timer target - share a plain-text exposure note for a shot list Why people pay for it: - long-exposure stop math is easy to miss when light is changing - the app focuses on stacking, timing, and readable field output instead of a generic camera toolkit - no account, ads, subscription, analytics SDK, or server dependency ND Stack Timer is a photography calculator only. It does not control your camera, access Photos, analyze images, or guarantee final exposure.