While we're currently house-hacking, it seems silly to have them snail-mail such documents.

It's completely free and can help you keep track of your rentals, documents, etc.

The credit unions I have talked to have told me they need 6-12 months of rental history before they will approve a HELOC on our rental house located in southern Utah.

If that gets documented, it allows  for immediate termination of the lease.  

Its worth mentioning, most homes listed will show tax payment history which will also give you an idea of what to expect.

If they show a "year gap" on their rental history I would "pass on them".

Does anyone know where can I find an investor's agreement document/template?

I am looking at a cash only deal to fix & flip.The house is listed for $325,000 (4 bed 2 bath 1500 sq ft)  The neighborhood I believe could support a case for $550-600 all fixed up.The house right next to it sold for $490 (3 bed 2 bath 1300 sq ft) In a document I received from the realtor it discloses there was water damage to the kitchen area. 

Currently we just save the invoice in Dropbox and edit a Word document to add up the invoices, and send it all over to the accountant.

Did the seller want any documentation to demonstrate that a loan was not going to be available?