Influx is absolutely amazing. We're using it along with grafana to store and display our desktop and web apps' analytics (it completely replaced GA), store and display HTTP health analytics (piping custom uwsgi request logger into UDP input), and do continuous analysis of Hearthstone games. It's incredibly fast and the grafana/influx/telegraf stack is really cool to play with. Highly recommended.
I am new to InfluxDB but I am interested in using it for some desktop app analytics. Are there any resources that you would recommend I start with? Maybe some from your own experience? How hard was for you to start using it for desktop app analytics?
Once you have this data, set up grafana and build some graphs to query it. Grafana has a graphical query builder, and internally it's essentially a sql-like. There's good tutorials in the influx/grafana docs for all that.