I don't personally recommend saving for investments, which takes forever, rather learning how to raise capital to acquire investments.

Are there any tools that you recommend?

I am looking for a recommendation of a contractor.

Carlos mentions that you can also exploit seasonality to get comparable profits like this, and recommends some ranges to seek remodels in (thank you for sharing those!).

Some HELOC lenders require you own the property for 6 months too, so I'd recommend to check that when shopping too.  

I wouldn't recommend Azibo, especially not for accounting.

Every system you try will have flaws, or you may salivate over a feature that appears in other software.Some familiar names are mentioned frequently: Stessa, Apartments.com, RentRedi, TenantCloud, Innago, RentManager, Avail, Rentec Direct, Doorloop, etc.I recommend conducting thorough research on each app online to understand their offerings, pricing, etc.

What creative financing options would you recommend for managing secured debt when traditional refinancing or selling isn't viable at the moment?

Has anyone read the multifamily millionaire book by Brian Murray and Brandon Turner?

Quote from @MarieChele Porter: I highly recommend you join the California Apartment Association.