I see this question has been posted for a long time, but I'll answer it for you. The cost for your study would depend on many factors. First and foremost, you would need to decide who your stakeholders will be (who will benefit from this app, and what organizations, groups, etc. would have an interest in this research?). You can then decide on who your subjects will be. The breath and scope of your study would need to be decided on next. An appropriate sample size would then need to be calculated (this is a process in and of itself). After this, you need to decide how best to test your app, and develop a methodology and procedure. Keep in mind that all of this I have mentioned so far would need to be supported by the relevant literature in the field or industry to which your app best applies. If you are doing this study for an institution, you must secure approval to conduct the study from whatever IRB (Institutional Review Board) your institution uses (This means you will have to write a proposal of some form). You are now ready to calculate what your study will (or should) actually cost! From there, you can search and apply for grants to secure the funds for your study. Grants is a whole other topic! Let me know if I can help. Good luck!

Hi Mr. Lee, I am not an expert on Apps, or App development, but I can offer a few tips. It sounds like you really do believe you have a potentially lucrative idea for an App. If you live in the US, the first thing I would do is file a temporary patent. You can do so here https://www.uspto.gov/ for about $100. The temporary patent protects your idea for one full year from the date the patent request is approved. This time is essential for many entrepreneurs who are just getting started with an idea, but may not yet have a working prototype, or otherwise need time to further develop their idea. To get a full patent, you will need to develop a "proof of concept", essentially a prototype of your idea (in your case, your App). Having a temporary patent will serve to not only protect your idea from being taken by another developer, but it may also help make your idea more attractive to investors, and potential business partners. I have gone through the patent process several times. Let me know if I can be of further assistance. Regards, Dr. James Bell