Unfortunately a Latex template is not available, and we do not accept Latex files as submission files, only Word documents.
A Word-template of an article compatible with journals from JMIR Publications can be downloaded from http://jmir.org/ojs/public/journals/1/InstructionsForAuthorsOfJMIR.docx. The references can be in any format, as long as the in-text citations are sequentially numbered in the manuscript with square brackets and as long as the reference at the end has a PMID in the format PMID:123456.
Please see the instructions for Authors page for further details: http://www.jmir.org/content/author-instructions.