A light box accessory for analyzing colorimetric strips with a mobile device, said mobile device including a central processing unit and a digital camera, the accessory comprising: an enclosure including a proximal cover, a perimeter wall and a distal cover, the proximal cover presenting a proximal face and including structure defining a view port that passes through said proximal cover, the distal cover presenting a distal face; an aperture structure that defines an aperture within said enclosure, said aperture defining a viewing axis that is concentric therewith, said viewing axis being substantially normal to said aperture, said view port of said proximal cover being substantially concentric about said viewing axis; astructure defining a first slot for insertion of a colorimetric strip, said first slot being configured for orienting said colorimetric strip to intersect said viewing axis, at least one light source disposed within said enclosure, said at least one light source being arranged for illumination of said colorimetric strip when said colorimetric strip is registered within said first slot; a power source disposed within said enclosure and operatively coupled with said at least one light source; characterized in that the light box accessory further comprises: an in situ calibration target independent of said colorimetric strip and disposed within said aperture structure of said light box accessory to cover only a portion of the aperture, said in situ calibration target having predetermined color characteristics; and a switch operatively coupled between said power source and said at least one light source for selective activation of said at least one light source, wherein said light box accessory is configured to communicate with said central processing unit of said mobile device only through said digital camera of said mobile device; and wherein the structure defines a second slot arranged proximate to an abutting end of said first slot, said second slot being configured for visually verifying insertion of said colorimetric strip into said first slot. an enclosure including a proximal cover, a perimeter wall and a distal cover, the proximal cover presenting a proximal face and including structure defining a view port that passes through said proximal cover, the distal cover presenting a distal face; an aperture structure that defines an aperture within said enclosure, said aperture defining a viewing axis that is concentric therewith, said viewing axis being substantially normal to said aperture, said view port of said proximal cover being substantially concentric about said viewing axis; astructure defining a first slot for insertion of a colorimetric strip, said first slot being configured for orienting said colorimetric strip to intersect said viewing axis, at least one light source disposed within said enclosure, said at least one light source being arranged for illumination of said colorimetric strip when said colorimetric strip is registered within said first slot; a power source disposed within said enclosure and operatively coupled with said at least one light source; characterized in that the light box accessory further comprises: an in situ calibration target independent of said colorimetric strip and disposed within said aperture structure of said light box accessory to cover only a portion of the aperture, said in situ calibration target having predetermined color characteristics; and a switch operatively coupled between said power source and said at least one light source for selective activation of said at least one light source, wherein said light box accessory is configured to communicate with said central processing unit of said mobile device only through said digital camera of said mobile device; and wherein the structure defines a second slot arranged proximate to an abutting end of said first slot, said second slot being configured for visually verifying insertion of said colorimetric strip into said first slot. an in situ calibration target independent of said colorimetric strip and disposed within said aperture structure of said light box accessory to cover only a portion of the aperture, said in situ calibration target having predetermined color characteristics; and a switch operatively coupled between said power source and said at least one light source for selective activation of said at least one light source, wherein said light box accessory is configured to communicate with said central processing unit of said mobile device only through said digital camera of said mobile device; and wherein the structure defines a second slot arranged proximate to an abutting end of said first slot, said second slot being configured for visually verifying insertion of said colorimetric strip into said first slot.