Construction Estimator and Bidding App seems pretty nice and comprehensive. 

I plan to hold on these properties for a long time, because my goal from REI is to have an early and comfortable retirement.Advice from BP members:Right now I’m reading books, listening to podcasts, and educating myself before I start with this journey.

The only problem is I don't know what niche would be the most advantageous path given my current path of formal education. 

The best places to look is under the education tab and there you'll find the ultimate guide of real estate investing and everything else you need to know about real estate investing and then go from there.

Terrence Redmond II I envision providing affordable housing to post-education students and other working professionals in the Pittsburgh area.

If you're light on money, just starting with no education in the industry, I'd think you'd do well to hit $50K as net income in your 5th year.Just a dose of reality!

It's the guru strategy that needs to be corrected and that will be done by education, hopefully.People don't learn what they don't want to know.

Make sure to check out Education for all your REI learning.

I'm a complete newbie, I hope to expand my real estate education by reading books and connecting with successful investors and of course using Biggerpockets!

It's great that you want to  be a professional, but that will require a real education, acting in a professional manner, legally and ethically.