SensorLab

After a bit over two years I now have over 100K installs from people on the play store :)
Conversions to the in-app upgrade is much lower though.

I have not done any marketing, mostly just people finding it from what I assume is browsing the store, and maybe word of mouth.
I also got quite a bit of useful feedback in the comments section, keeping on top of bugs for all the different devices out there is quite the challenge.