I just did an analysis of 5 PM Software Tools for DIY Landlords under $20/mo. I was not able to find any recent comparisons in the last year and since features and pricing change over time, wanted to share my research. The analysis is targeted to small time DIY landlords with 1-5 properties with minimum requirements to be able to do the following tasks online: Listing/Syndication, Applications, Screenings, Leases with eSignature, Payment Customization (i.e. Recurring, Single Time Fees, Late Fees) and Tax Support (export financials for tax reporting).

Summary:
Inaggo is the only completely free option that meets the requirements. The only drawback was it did not list/syndicate to as many sites. Standout feature include the ability to completely customize a lease with fillable fields and eSign.
TurboTenant only provides eSign with the Premium version but it meets t$12.42/mo. Some impressive features including extensive listing/syndication and state specific guidance provided such as max security deposit.
RentRedi is a flat fee for the most part and has some cool features like pre-qualification and integration with QuickBooks. Requires you to upload a pdf lease from outside the tool for eSignature.
TenantCloud only had the Starter Plan under $20 and was a bit difficult to determine what was included. The 14 day trial requires your credit card information. Major drawback was the starter plan did not allow you to customize a lease.
Avail had very basic functionality and was missing features such as income verification.

They all require a fee for ACH and Credit/Debit, but Inaggo and TurboTenant allow for offline payments such as Venmo, PayPal, and Zelle. Based on research it appears Zelle is the only option that does not have a transaction fee for landlords.

I did not include maintenance as a category since this can be done easily in a spreadsheet, but all of the options actually had pretty good maintenance and expense tracking.

For Tax Support, all of the tools met the minimum for being able to export the financial information.