The business model is fairly simple, they buy them at a discount from people who need / want the cash and resell them at a smaller discount.

There are couple business models for running mobile home park business but the most successful one is when you own only land and tenants own their mobile homes.If you want to invest only in mobile homes, I recommend @John Fedro .

The business model is viable, and joining Berkshire Hathaway just feels "right" to me.

I think you should decide what you want your end business model to look like and then once you know how this will look in 5-10 , 20 years that is your goal.. then you create a strategy to fit that goal ( Whether it is cashflow, depreciation, appreciation, equity capture, etc...) then you find deals / Turnkey / PM etc... that fit your desired needs and what kind of purchase you are looking to have to fit those needs.. 

I know LLs that do it and like it, so it really depends on your business model.

Also, please post here the iOS software specs, and your phone model. 

Is it the detail you want or know and does the model of the calculator have the correct assumptions and inputs as what you do or want?  

@Mark Brazier  Great Question  @Michael Smith  in our funky staty of Orygun .. if your trying to start a LLC or Corp.. and register it in the state.. any reference to capital lending etc. you will need to give a detailed description of your business and or business model and have it approved by the division of finance and corp securities...

I chose to put a hold on College because i didn't see how it fit into my core business model of becoming a real estate investor.  

Is it a California regulation, or perhaps a looser model that the crowdfunders might look to?