I'm now at challenge #13 and have no clue how to proceed further, I even revealed all tips for this one, but nothing is happening. (I suppose the start service command contains a typo, as it would require root, but removing the errornous word allowed me to start the service). I also see that the service is started in the developer tools, but 'sending the message' (being vague to not spoiler things) doesn't change anything in the Challenge.

For the previous challenges I haven't had any problems, finding the correct tools for each challenge wasn't really hard. But #7 and #8 were stressing me out, not because the "developer part" but the challenge itself, as I needed to remember things and be fast.

But I think the tips website is really well made! And the challenges that weren't tedious were quite fun, as it was cool to see how the developer tools can be (ab)used to created challenges like these!

Thanks for this feedback! You're right, the start service command did contain a typo. The action had a typo in both code snippets too. I've updated the dev docs for this, verifying that the code snippets now work in the app.

I've heard similar feedback on #7. My plan is to reduce the digit count from 6 to 4, which should still prove you understand how the puzzle works, without making it unnecessarily complicated.

Thanks again for the feedback! I hope this helps unblock you and that you have fun with the rest of the game.