About JustIn
Origin Story
JustIn was originally conceptualized by a group of academic mHealth researchers who were tired of reinventing the wheel for each new study. Mobile health studies need apps, and apps are difficult, expensive, and time-consuming to build. We found ourselves and our colleagues starting from scratch with each new app, because reusing the previous app code was infeasible. Often the original developers had moved on, leaving behind code that was not documented or designed to be reused, rendering it more or less useless. We tried various approaches to streamline app development, including commercial vendors offering mHealth research platforms, but always found that they were not quite able to do everything we needed, so we found ourselves writing large chunks of application code even in those situations.
To break the cycle of discarded apps and wasted effort, we decided to create JustIn. We are building JustIn as an open-source, freely available platform consisting of reusable software components that can be composed into mHealth applications with relatively low effort. Our work across many years and many projects has allowed us to identify common requirements and patterns that appear over and over again and that nobody should have to build from scratch. JustIn provides features that address these requirements and streamline the use of these patterns. Moreover, JustIn will continue to grow to include additional components through the ongoing work of the core team as well as contributions from the broader community of JustIn developers.
JustIn Vision
Our goal for JustIn is to significantly reduce the effort and cost required to build apps for mHealth research, especially apps designed to deliver adaptive interventions, which are interventions that modify their operation based on user characteristics, behavior, context, and/or outcomes. Currently such apps require significant software development skill and effort to build and delploy, placing excessive burden on research budgets and investigators, who may struggle to find sufficiently skilled development expertise at a price they can afford. While JustIn is designed (for now) to require programming, our goal is to make that programming signficantly easier, faster, and cheaper. In fact we use the "undergraduate in CS" as our benchmark for who should be able to use JustIn to build an adaptive mHealth intervention app that can withstand the rigors of a multi-month trial with dozens or even hundreds of participants. As researchers mostly working academia, we are intimately familar with the skills, availability, and costs associated with student developers, and know that being able to build mHealth research apps with students will greatly accelerate research while providing excellent experience for students still building their craft.
JustIn will initially be released in several stages, with each stage adding more of the functionality required to build a complete app. See the JustIn Roadmap for more details about planned features and approximate timelines.