BPM tool comparative:
Kissflow allows the automation of simple processes, as it is a very simple tool. But this is often a problem, given that growing organizations not only have simple processes to run, and those complex processes require a better support system.
Pipefy is a very simple BPM tool, but with a UI that is not adaptable to the user. Often, this leads to leaving some business needs unattended, which reduces the adoption.
Process.st is a checklist software, not a Business Process Management Suite. It does not support real business process, with Workflows, and it does not work with BPMN, the international standard.
AuraPortal is based on the old BPM paradigm, installed on-premise. It requires a long investment and a large IT team to take full advantage of the tool. It lacks a Software as a Service model, where you can try the tool beforehand.