Somebody is using a database (sqlite in this case) to store JSON objects. There is nothing strange or unusual here.
When doing this, though, the problem is that it's more difficult to run search queries with the same expressiveness as we would otherwise do had the data been properly "unfolded" into many columns of a relational database.
This tool allows to make such expressive requests. This is very useful.
Interestingly the search query itself is expressed as a JSON object (this is a design choice, it could or could not have ben the case. In any case it's cute.)