-
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.
I use Simple Gallery Pro because it plays gifs. It's also open source and has no ads. You can find it on f-droid.
Here is another one that doesn't get mentioned a lot: QuickPic Gallery
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.