It also counters rampant online misinformation - such as that smelling red onions is effective against coronavirus - and uses crowdsourcing to help hospitals find protective gear.
A bigger function is to give a more realistic picture of the extent of infections and deaths in Indonesia than the official version.
Some data was withheld early in the epidemic to avoid panic, President Widodo has said. But a promise of a new website to share all data transparently has yet to be realised.
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Indonesia's official figures show 22,750 infections and 1,391 dead, but officials have said the deaths only include those who have tested positive for the virus. The main doctors' association says the figures could be higher because Indonesia has among the world's lowest rates of testing.
Kawal compiles raw data from provincial governments and hospitals that also shows those cases and deaths for which doctors can see no reason other than coronavirus - but which were never tested.
According to Kawal's calculations for 22 of Indonesia's 34 provinces, at least 4,016 Indonesians have died with acute symptoms of the coronavirus.
That could make the death toll well over 5,400 - about four times the official figure.
"With data guarded centrally during the pandemic, it's a good thing that there's people who want to provide help from the outside," said Shela Putri Sundawa, a Jakarta hospital doctor.
