For what it's worth, I'm actually writing and Android app for pipe smokers
I'm a somewhat newbie pipe smoker (started ~2 years ago, but only taking it more seriously in the last 8 months or so), and at some point I got tired of keeping my notes spread between a spreadsheet, Trello, Google Keep, paper notebook etc. And I couldn't find an Android app to help me. So, what the hell, I decided to write one
I wasn't going to mention it on the forum yet, but it seems relevant to this thread. The app is still in early stages, but it works and but I'm managing to get some work done on it every day. It's not released in the Play store yet (and, for what it's worth, my current intention is to make it free), but I'm running a Beta group and I'd be happy to include anyone here that might be interested.