There are a million tools out there to create apps: from phone gap that will help you make an app out of a collection of HTML pages, specific tools like Epic's GoMo which have interactions aimed at learning, clear language programming like LiveCode that will allow you to use the camera and GPS on the device and the more complex full development environment.
I would ask a few questions:
-Who is your target audience? (what devices do they have, how tech-savvy are they, how is there connectivity etc).
- Can you get away with a website?
- Are you going to make a single APP or multiple ones? (or a single App with multiple pieces of content - my favourite).
- Do you need tracking? Are you expecting the App to connect to your LMS?
Take a look at the research tag on this project: http://www.mole-project.net/research if covers different technical environments for app development but I would find it an easier question to answer if you had some more info about the project and your objectives.
Hope this makes sense,
I am involved in an European project MIRROR Reflective learning at work. There are about 20 reflective learning apps developed that are based on our relective learning model. Maybe there are some apps that you would be interested in. Have a look at http://www.mirror-project.eu/showroom-a-publications/mirror-apps-st.... If you are, please contact us to see what we can do for you.