As it is, I've gone back to just keeping paper receipts in a file folder and electronic receipts in a gmail folder.

If the tenant has paid every time on time with no issues it’s a simple mistake probably a electronic timing glitch. 

If the software is not simplifying your life or making you more accurate, you shouldn't use it.Software does have extremely helpful features like online payments, marketing syndication (click a button and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

I use KeyCheck, a FF affiliate, for background checks, lease agreements (available for all 50 states) and electronic signing, and payment processing including credit/debit card payments.

I recently looked into doing docusign route, but was unsure if I could have the notary sign after the tenants have signed electronically. 

Partially because you did not rent it for an entire year but mostly because of upfront expenses: getting it ready for rent, buying furniture, electronics, and other furnishings, stocking up on initial supplies, and so on.

Are they efficient at doing the electronic payments from the tenant's account to the landlord's account?

I don't know if this is one of the new things or not, but this is now in there under 3.7.7, "You also acknowledge and agree that we may on occasion offer discount pricing for your Property; provided that (i) any such offers will be available with respect to a broad number of Listings and not limited to your Property; (ii) we will provide you with electronic notice of such discount(s); and (iii) you may opt out of a particular offer."

Electronic keypad deadbolts.