My brother and I have this really cool idea for an online app that could potentially make a boat load of money.
Let's take this back a second...replace the 'brother' bit with 'friend' 'colleague' 'associate' 'guy I met at the pub last night'...put in the rest, and you have effectively the beginning to the many business startups that end in debt and loss.
They all thought they had an idea that could make boat loads of money. Unfortunately they forgot some crucials.
While I won't go into business 101 with you, my advice is, before you go getting someone to design your app, and paying him, think about this...how will you get it to the marketplace?
I realize there is google play and many others, but that is not the question...that is the equivalent of putting it on the top shelf on an isle in a giant warehouse that stocks literally millions of other apps. My question is how will you get word out to the masses that your product exists, and that they should walk past all of those other millions of apps to get to yours and then spend money to buy it?
It does not matter how much sense the product makes, or how good it is when answering this question. It could well be the greatest app ever made in the history of cellphones and tablets, but none of that matters if it never gets noticed by a lot of people straight away, and it must be straight away because apps don't gain momentum the way some other things do...they have a limited amount of time in which they stay appealing before the people that did take interest go over to the newly created competition.
I don't say this to discourage you, I say it to make you step right back a second and do the maths, not the happy maths where you say well if 1% of the population of this group bought my product then I will make this amount after expenses...I mean the real maths...where you realize that the only real way to reach such a large population quickly is probably on tv, which will cost mega bucks, or by talking on certain pages etc online which won't cost you much but won't bring you many customers either, mainly because even if people think its good, suddenly they have to pick up their cellphone, and their wallet, and that is work and expense in their relaxation time so they will more often then not put it off until tomorrow and then forget its existence overnight.
So do the maths.
Last point...Is there anywhere online or offline where they can get, even to a lesser quality, the service that your app provides? Because people are notoriously eager to go the extra mile to get things for free rather then getting it faster, easier, and packaged if it costs.
I sincerely and earnestly wish you the best, and you don't need to answer my questions or justify your choices to me or anyone else...but as a guy that has had failed businesses myself, and seen others with the same end result, I would hate for you to join the club that I am now a part of a few times over, due in no small part, because we all thought that we had a product or service that could potentially make boat loads.