Custom mobile player development?

Hi everyone,

Being that I work for a governmental organization I would like to look at the posssibility of developing our own mobile player for our content. Using a commercial app is not likely to be an option for us long term. I am out of my league at this point and have no idea what the level of effort could be for such a project.  I do have access to IT and programmers but would like to do some digging before I go to them. How long could it take to do? Would this type of player be developed using html5? Using an apple development account? Where do we start?

Thanks in advance for any advice on this.