Notes

Building AltClock as BlockClock's Twin

Published 2026-09-14 · 6 min read

AltClock's whole premise is one sentence: live prices for every coin except the one that works. It's a Bitcoin-maximalist, deadpan clock for the rest of the market — the coin you're holding, how far below its all-time high it currently sits, and a one-line verdict delivered without much sympathy. It exists because BlockClock already existed, and once a Bitcoin split-flap clock was working, the joke of pointing the same board at everything Bitcoin isn't was too obvious to skip.

The idea

BlockClock is earnest: a Bitcoin dashboard that just reports the chain. AltClock keeps the same hardware-style board and the same commitment to real numbers, but turns the narration sarcastic. It tracks Ethereum, XRP, Solana, and more than forty other coins, filters out stablecoins and wrapped tokens so the "how far has this fallen" numbers stay meaningful, and reports the same three questions for every one of them: what is it worth right now, how far below its peak is it, and what multiple would it need just to get back there. Bitcoin dominance — the share of total crypto market value that belongs to Bitcoin, next to everything else combined — sits alongside as a fourth reading, because the running joke needs a scoreboard.

Four views, one board

Clock puts a single coin on the split-flap board at a time: price in dollars or in satoshis, distance from its all-time high, market-cap rank, its move over the last 24 hours, and a verdict line attached underneath. Market lines up every tracked coin in one table with today's move and its drawdown from peak, plus a running count of how many are actually green on a given day — usually a short count. Graveyard sorts coins by how far they've fallen and shows the multiple each one needs to claw back to its old high, which is the view that turns "it's down a bit" into an actual number. Reality is the scoreboard: Bitcoin's share of total crypto market value against everything else combined.

Two of those ideas — distance from an all-time high, and the multiple needed to break even — get their own plain-English explainers, because the numbers are simple but the framing trips people up constantly. If you want the full breakdown rather than the one-line summary, they're linked from inside the app: what distance from ATH actually measures, and how the break-even multiple is calculated.

Live data, with a fallback for when it isn't

Prices come from a public market-data API, refreshed roughly once a minute, with no key required and no server of mine sitting in between. When that API is slow or rate-limited, the board falls back to a small set of seed prices rather than showing a blank board or a stalled number — a coin can read slightly stale for a moment, but it never reads as broken. Stablecoins and wrapped tokens are filtered out with a structural check rather than a hand-maintained list, because a "top altcoins" board that includes a dollar-pegged token sitting at 0% from its all-time high isn't telling you anything useful.

Built by copying, on purpose

Almost none of AltClock's foundation is new work. It shares BlockClock's design language outright — same layout system, same split-flap board mechanics, same stylesheet structure, with the accent color swapped from gold to a lime green so the two are never confused for each other at a glance. Both apps support English and Thai across every screen, including the sarcastic verdict lines, which exist in both languages rather than being written once and translated as an afterthought.

The clearest example of the copying is the share-card feature. Neither Instagram nor Facebook expose an API for posting directly to a Story from a website — that integration only exists for native apps registered with a platform app ID. The only thing that actually works from a browser is generating an image and handing it to the operating system's own share sheet, so a person can pick Instagram themselves and post it as a Story in one more tap. AltClock draws that image the same way BlockClock does: a canvas-drawn 1080×1920 PNG, built from the same code, reading its colors from CSS variables instead of having a separate color path hard-coded in. One drawing routine produces a gold card on BlockClock and a lime-green card on AltClock without knowing which app it's running in — it just reads whichever tokens are active.

Every AltClock screen carries a chip pointing back to BlockClock, and the reverse is also true. Neither app is trying to be the only thing on your second screen; they're built to hand traffic to each other, the way a two-window bit would.