Portable　electronic　devices　and　wireless　communication　enable　a　broad　range　of　applications　including　environmental　surveillance,　food　safety　monitoring　and　point-of-care　testing.　Particularly,　by　incorporating　smartphone　and　microfluidic　paper-based　device,　rapid　analysis,　mobile　laboratories　for　chemical　assay,　remote　sensing　and　data　management　become　more　available.　In　this　work,　we　designed　and　fabricated　a　12-unit　paper　chip　for　colorimetric　detection　of　metals.　48　chips　can　be　obtained　on　a　single　A4　size　paper　within　5,　min.　Additive　manufacturing　technology　was　employed　to　construct　the　experimental　platform.　A　cellphone’s　camera　was　used　to　capture　colorimetric　images,　and　then　the　RGB　values　of　the　color　images　were　converted　to　grayscale　via　a　self-built　App.　The　intensity　reflecting　metal　concentrations　were　processed　and　analyzed　by　the　same　app　and　a　remote　server.　To　demonstrate　the　utility　of　this　approach,　Fe　solutions　were　tested.　The　detection　limit　of　this　method　is　0.2,　μg.　The　presented　device　and　data　processing　tools　hold　a　potential　to　assist　mobile　sensing,　pollution　detection　and　healthcare　in　routine　work.　©　Springer　Nature　Singapore　Pte　Ltd.　2018.