You're probably here because you want to test the stuff I've got on github without having to bother with npm and building the code yourself.
Rules of the game (please take time to read ALL of this): builds happen when I commit code. Builds are throttled to one build every 6 hours (but I can make an exception). If the extension was built less than 6 hours ago and I make a commit, the extension will be rebuilt about 6 hours after the last build.
When testing development version DISABLE THE STORE VERSION OF ULTRAWIDIFY OR USE A DIFFERENT BROWSER PROFILE. Otherwise, both versions of extension will run simultaneously — and that may be bad.
Versions of ultrawidify published here are intended for testing, not normal use. Because of that, there's some downsides: a) no automatic updates, b) extension might be a broken mess.
Nightly versions ('nightly' folder) get built often and automatically. Since they're built from the last commit, nightly versions might be everything from functional to completely and utterly broken. If you want to report bugs and isses from nightly versions, use discretion. It's very likely that I'm aware of vast majority of issues that pop up in nightly builds.
Testing versions ('testing' folder) is ... well. If a person reports a bug that I cannot test, I might build a special version that will either gather logs (presently, all logs go to browser console and have to be pasted/screenshotted manually) or contain a possible fix that I need said person to test. Github issues may (but may also not) provide additional info about the purpose of a build.
Another option is to create a new browser profile (Firefox, Chrome). This is the recommended option, but may require extra effort compared to the other one. You won't need to disable the mainline version of ultrawidify.
Download or Install .xpi (Firefox) or .crx (Chrome/Chromium/Opera/chromium IE) file. Not currently possible. Maybe some day.
Install unpacked extension. If you're good enough to snoop here, you should know to do it.
NO BUT SERIOUSLY, DON'T FORGET TO DISABLE STORE VERSION OF ULTRAWIDE WHILE TESTING.
Version numbering: YYMM.DD.[build number]. The higher, the newer.