As Google has now introduced admin tools to disable Google Groups, this experiment no longer works for most people in managed organizations (schools), but is still worth a shot.
I found a method to make Chrome Apps "unblockable" by usual admin controls your IT department has. This method leverages the use of "test" Google Groups, a method of publishing private versions of your Chrome App for testing, meaning anyone not in the Group cannot see the app when they look it up (both by name and by ID), and preventing it from being properly blocked. This method has worked for hundreds of students around the US, with not one report of a successful block before the new admin control disabling Google Groups.
The Google Group join code is in my Discord server, as to not make it too public: https://discord.gg/7xXGMfK