.- How much money do you have to spend?

You spend a giant pile of money before you make a dime of revenue.

Learn to control your spending and pay off debt.

By the time I retire, I want to have enough rental properties to have financial independence to enjoy my hobbies and enjoy spending time with my family and watch my children grow up.

You definitely wont get an app like that for free, so how much would you be willing to pay to a company to submit it for you, vs spending 10 minutes once a month to submit taxes? 

It seems not the best way to spend money.

Mark Cuban didn't "wait" until he could start at billions.

There are multiple billion dollar companies dumping money into the city, such as Intel, Google, Honda, and Amazon.

THEN, I plan to purchase the second home using a FHA or conventional loan (3%-5% down), for which I will likely pay the monthly cost out-of-pocket, maybe with some rental income support if it is a duplex.My concern is, I do not want to spend my savings or weigh down my debt-to-income ratio so much so that I cannot qualify for and pay the down payment and closing for the lending on the second home.Questions: - With the first home being multi-family, 75% of the rental income (or potential rental income initially) will relatively either maintain or boost my debt-to-income ratio from lenders' perspectives, right? 

If you want it to run well, you may be spending a lot of time at the property.