Turn your reviews into ATP. Powerhouse is a small idle game that runs on your Anki reviews. Every card you answer makes ATP for Mito, your mitochondrion. Spend it on metabolic pathways, from glycolysis to ATP synthase to mitochondrial biogenesis, so every future card is worth more. It stays out of the way while you study and is there when you want a reward afterwards.

Built so it never bends your studying

• Any button, same ATP. Again pays exactly what Easy pays: the button you press never changes what an answer earns.
• Speed never pays more. "Flow" only asks you not to wander off for more than 3 minutes.
• Fair play. Mashing through cards, looping one card, or letting auto-advance answer for you quickly stops earning anything. Reviewing at a normal pace is almost never affected.
• Read-only. Powerhouse never changes your cards, scheduling, decks or sync. It reads the review log, nothing more.
• Quiet. A small pill in the bottom bar while you review. The game window only opens when you click it.

What's in it

• 10 pathways to build, each with upgrades, plus study-habit upgrades (coffee, sleep, a qbank streak…)
• Vesicles drop about once every 40 cards (less often late in a big day). Open them for ATP, 48 collectible enzymes (each with a high-yield fact) and outfits for Mito
• A new enzyme set with every title from Pre-med to MS4. Every legendary is a rate-limiting enzyme, and duplicates raise an enzyme's expression level. Bad-luck protection: never more than 2 duplicate legendaries in a row while you're missing one
• Paced for the long haul: at about 250 cards a day, the full codex takes about 6 months
• A daily goal with a streak (finishing every due review counts too), and freezes that cover a missed day
• Three daily quests that adapt to how much you usually study
• 56 trophies, levels, and Fission: Mito grows as you build, then divides, keeping +25% ATP per mtDNA copy forever
• Built for heavy days too: 1,000 to 2,000 cards a day is fine
• An illustrated in-game guide (the ? button)

Works with how you already study

• Phone reviews (AnkiMobile, AnkiDroid, AnkiWeb) count once you sync on your computer, even weeks later
• Undo takes back what an answer earned
• Tested with FSRS, image occlusion, cloze, filtered decks, night mode, AnkiHub and custom background add-ons
• Your game is saved in the add-on's own folder and survives updates

How to use it

Review like normal. Open the game from the Powerhouse button in the top bar, the card under your deck list, or Tools → Powerhouse. Settings are in the Stats tab of the game window (daily goal, where the pill sits, sounds, reduced motion).

New to it? Read the illustrated guide: How to play (PDF)

Requires Anki 23.12 or newer on a computer. Add-ons don't run on AnkiMobile or AnkiDroid, but reviews you do there still count.

Feedback and bugs: please use the support page link rather than a review, so I can reply. Open source under the AGPL-3.0: source code.