Steps to reproduce:
- Open the app.
- Choose any site.
- Click the site name and choose "users."
- Click the site name and choose "tags."
- Click the site name and choose "users" again.
- Observe crash.
I'm using a Galaxy S4 with Android 4.3.
That was a weird freaking bug. My first reaction was "Huh that's neat, I wonder why that happens", then I realized it's my job to actually figure out the answer to that... Fixed in version 0.1.81 coming out around midnight UTC.
In case anyone is wondering about the "why" like I was, it turns out the android support library's version of FragmentTransacation.replace() is broken and has been since 2011, due to (seemingly) a copy-paste typo.