-
InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
Then this GBAtemp thread has links to a lot of useful resources, Foxi4's tutorial is a good introduction to the basics and just looking at devkitPro's examples (can be installed by pacman or it's on GitHub) is a good place to start, GBATEK is also very useful for low level info on the hardware.
NOTE:
The number of mentions on this list indicates mentions on common posts plus user suggested alternatives.
Hence, a higher number means a more popular project.