I am making an app just for my nephew who loves trains. I had to re-engineer the whole thing to be browser based because he has an iphone and apple make it impossible to make software specially for one person and have them actually install it.
Now #android is going to be doing the same thing.
"Sideloading" is just corporate speak for "installing software". If you own it, you should be able to do what you want with it.




