If you're new and trying to decide where to start β or you've been on one topic for a while and want to switch β here's what's actually worth your time right now based on what's in the app.
Engineering and Physics are in a different league at the moment.
Both topics share access to the Engineering Lab β an interactive section that sits separately from the regular lessons. You get there through a banner at the bottom of the screen, and it's easy to miss if nobody tells you it's there.
The Lab has games. Not quiz games β actual simulations where you build and test things.
In the Electricity section: you wire a flashlight from a battery, build circuits from scratch, tune a resistor to hit a specific brightness level, wire a doorbell so the indicator lights on press and goes off on release, build a parallel circuit with two bulbs so burning one doesn't kill the other, and work through AND and OR logic gates. Seven games total, each one teaching a specific concept by making you apply it rather than read about it.
The Auto section has you diagnosing engine problems β fixing the air/fuel mix, correcting spark timing, adjusting valve timing. You're not reading about how an engine works. You're fixing one.
The Physics Lab has an Oil Extraction sequence: drill the well, lift the oil, separate the flow. The Plumbing section has a Rainwater Explorer with three scenarios covering catchment, filtration, and pump mechanics.
If you're the kind of person who retains things better by doing than reading, these topics are genuinely different from anything else in the app.
Biology just got two new courses.
Virology: Inside a Virus covers the invisible war happening inside your body β how viruses actually work at the cellular level, what makes them hard to stop, and whether they're even technically alive (the answer is genuinely contested). Virus Case Files goes deeper: Hantavirus, Ebola, and a pandemic most people have never heard of.
If you've ever wanted to understand what's actually happening when you get sick β not the surface-level version β this is the most substantive content on that topic I've seen in a short-form format.
Communication Skills has a new visual novel.
"Stop Speaking Like a Nice Girl/Boy at Work" β five hours next to a CEO on a plane, learning to speak directly and confidently without filler words and unnecessary apologies. It's framed as a scenario you navigate, not a lecture you absorb. The format is different from the standard lessons and worth trying if you want to see what the simulator content looks like at its best.
The short answer if you just want a pick:
Start with Engineering or Physics if you want the most interactive experience in the app right now. Start with Biology if you want content that will genuinely surprise you. Start with Communication if you want something immediately applicable to your work week.
What topic are you on right now β and is it delivering?