For creating native apps outside the app store, you can either use the a compiler and write your app in C (objective-c I think)
or you can use Jiggy which is written in java and does not require setting up a compiler
the (unofficial) compiler is available for mac/linux/windows; a good tutorial on starting is
here
I think that jiggy is much easier to learn and install so I would recommend using it instead. More info on it can be found
here
I actually made
a scouting app this season using Jiggy feel free to use, learn from, or expand it.
download