Rent due and collected
Rent shows what is due across your portfolio and what has been collected. Record each receipt against the lease it pays, not as a loose payment: that is what clears the tenant's balance, feeds the owner's payout and keeps arrears honest.
Record part payments as they arrive. The balance stays outstanding and keeps appearing until it is paid, which is exactly what you want.
Invoices
Invoices covers anything billed beyond scheduled rent - a service charge, a repair recharged to a tenant, an agency fee. Issue it, then record the payment against it when it arrives.
Installments
Where an amount is agreed to be paid in stages - a deposit by instalments, arrears being cleared over months - Installments tracks the schedule and what remains, so a plan does not live in somebody's memory.
Expenses
Expenses records money spent on a property: repairs, utilities, service costs. Attach each to the property it belongs to.
This matters more than it looks. An expense recorded against a property reduces the owner's payout correctly and appears in their statement, so when they ask why this month is lower, the answer is already there with the invoice attached.
Owner payouts
Rent collected belongs to the owner, less your fee and any expenses. Owner payments calculates this and records what you have paid out.
Payouts follow the ownership you recorded: unit-level where it exists, otherwise the property's, and split by share where a property is co-owned.
The habit that keeps this right: record rent against leases, expenses against properties, and pay out what the system calculates rather than a figure worked out separately. The moment those two diverge, every owner statement becomes an argument.
Chasing arrears
Arrears are simply rent due that has not been received. Work from the rent screen rather than memory, and record every payment as it lands - a tenant chased for rent they already paid is a relationship you do not get back.