I made PortDroid, an Android Port Scanner and networking toolkit back in 2014 because I was learning programming and was curious to what was possible. I mainly wrote it for myself and I've done no marketing so have been quite surprised how popular it has become (~800k downloads).

It's been a consistent passion project for me now over the years and I love getting feedback and suggestions from people using it. It'll never have ads (I hate them) and only data collection is optional crash reports.

https://portdroid.net