Reciprocitize is a tool for long exposures on film or digital with reciprocity correction and filter offsets to remove the mental math and make your life easier!
The app includes corrections for the most common Foma, Harman, Ilford, Kentmere, and Kodak film stocks. There is also a custom mode where you can set your own values if using a film that is not included by default. If your dont need reciprocity correction, when shooting digital for example, simply disable it with the button in the top left.
Reciprocitize also features a filter correction setting where you can take away the mental math and quickly get your adjusted exposure when color or ND filters.