I am watching the crash free rate of my app, but it doesn't make sense.
According to my monthly data, I have 99.91% success rate, but on tendencies I can see that 89k users had a problem during the month. That would mean that those 89K UNIQUE users represent 0.01% of the total users (or total unique users with session) of the app, which would be around a 100 million people, which is muuuuch more higher that my app usage (less than 10 M).
So What does the crash-free rate really measures?
I have the theory that it instead is the "average" of daily crash-free users. (users that didn't have a crash on that day / users that engaged the app that day). Which is the opposite to what google explains on this metric: https://firebase.google.com/docs/crashlytics/troubleshooting?platform=android&authuser=2&hl=en#cfu-calculation
The Crash Free Users data comes from Analytics. This could create some differences between the information provided by both SDKs.
The Firebase team has improved how the Crash Free Users stats are being calculated and now the tooltip over the "?" also provides more information on how the percentage is calculated.
Here you can see the discrepancy I mentioned between Analytics and Crashlytics. But most importantly you can see the actual numbers used for calculating the Crash Free Users Percentage.