In Germany phyphox is quite popular in physics education.
However on android the sampling rate of the acceleration sensor is limited to 50/s. At least if you install through the official app store.
[1] https://iopscience.iop.org/article/10.1088/1361-6552/aac05e
My understanding is that it’s the same even on iOS (or at least on my iPhone SE 2020). More specifically, the output only measures till 50hz (but the sensor sampling rate is actually 100hz - Nquist, you need double the measured frequency as sampling frequency, yada yada.)
The sensors have analog lowpass filters that can be adjusted in order to avoid aliasing.
In general, with more bandwidth you can do more intrusive things. But if you want to tell wether two people ride in the same car, 50 Hz should be sufficient anyways.
Phyphox has a smartphone sensor database:
Edit: no, it can't have. Then the phone sensor database would show that since it is built from submissions within Phyphox: https://phyphox.org/sensordb/
I'm not sure what problem you're running into (perhaps a very unusual phone that has only a 50 Hz accelerometer) but Android/Phyphox can do way more than 50 Hz
But I see Google indeed introduced another permission for this: https://developer.android.google.cn/develop/sensors-and-loca...
Curious that the database shows good rates but you're not seeing it in your instance. The device is from 2024 so it'll have shipped with this new restriction; the database submissions can't be from an older android version. Phyphox must declare that permission or else it shouldn't be in the database like that, but then you should also see higher rates in the app. So I don't get it but Android still can do more it seems, if an app is granted the new permission