When I came out to LA to begin taking over my parents' RE business, the very first thing I set out to do was get our accounting in order. Their "system" was even worse yours; some of our tenants pay the rent in cash and it was not getting logged. We would often forget which contractor did what job on what property for how much, and whether we paid them or not. It was just really, really bad and we just were completely blind on our numbers.
Initially I studied QB for Landlords and even set up our accounts/chart of accounts. But I just didn't have the time to get proficient at it while at the same time starting up brand new construction of a 4-unit MFH in DTLA as well as take over all the landlording tasks.
So, just as @Linda Weygant mentioned, I just set up two Google sheets, with the primary goal of making it easy for data entry on the fly. The rental income tracker is very basic and has what you'd expect something like that to have.
The expense/job tracker is a little more involved but not much. It tracks all the jobs we contract out (labor and materials). It tracks the job status itself, as well as the payment status.
Here's what my Vendor Job & Pay Status Tracker looks like:
There's some custom validation and dropdowns I put in there. It also has some basic level filtering and reporting.
I spent about 2 hours on it so obviously it's fairly basic, but it does the trick really well. I love being able to just open this thing, and immediately know which jobs I'm waiting my workers to finish, or to see if I'm all caught up with paying them. I can set up some filters to report which contractors got the most business from us, how much we paid them monthly/yearly, and if we might think about negotiating better rates.
Again, for me the most important thing is to be able to quickly input data via mobile while I'm out on a job site talking to contractors. I'm managing close to 30 properties and it's so easy to forget this kinda thing.
I'll probably revisit QB later this year.