Anthony Crisp

I build small, careful software.

Mostly Android and the web, usually for a problem I have myself. I like projects with a hard constraint at the centre (no signal, no permissions, no resampling) because the constraint does most of the design work.

Work

Antinode
ongoingIn testing
An Android music player that controls the whole audio path to a pair of Bluetooth earbuds, not just the part before it leaves the phone.
Play a 44.1 kHz file over Bluetooth and something in the chain almost certainly resamples it, silently, every time. Android pins the A2DP stream to one sample rate when the codec is configured, and with LDAC enabled it defaults to 96 kHz, so every 44.1 kHz file you own is converted on the way out.
Other players can tell you this is happening. What they cannot do is stop it: changing the A2DP codec configuration needs a privileged permission no ordinary app can hold. Antinode matches the link rate to the source instead, downsampling hi-res by integer decimation and never crossing the 44.1/48 boundary, the one conversion genuinely worth eliminating.
No module in the app declares a network permission, so it has no way to phone home whatever it is doing to your audio. It is in testing now, ahead of a closed beta.
KotlinJetpack ComposeMedia3A2DP / LDAC
- antinode-audio.com
Boomer Solitaire
2026Released
A calm, dignified Klondike for Android. No ads, no accounts, no tracking, no internet. Provably.
The manifest declares no permissions at all, so the app is structurally incapable of phoning home. That is the feature: not a promise in a privacy policy, something you can verify.
Every deal is winnable unless you ask for otherwise, because a built-in solver proves a winning line exists before the deal is offered. Unlimited undo with no penalty, hints that prefer uncovering hidden cards, and a continuous auto-save that survives process death, rotation or a week away.
KotlinJetpack ComposeRoom
IDS Collection Tracker
2020 to 2025Released
Catalogue and map a rare tree collection, for members of the International Dendrology Society: a field app for recording specimens, and a website for browsing, filtering and exporting them.
Built around one collection in particular: several hundred Quercus on an estate in Norfolk, catalogued outdoors and often with no mobile signal. That constraint shapes everything, because recording has to work standing in a field with no bars, and reconcile later.
A shared core package holds the domain types, document mapping, filtering and geo that both clients agree on, written against the shape the data takes rather than against either Firebase SDK, because the phone and the website use different ones.
TypeScriptReact NativeExpoNext.jsFirebase
PawSafe
2025Paused
Open-source PWA for community reporting of broken glass on footpaths, for dog walkers and local councils.
Offline-first, with an IndexedDB store synced to Firebase, so a report made in a dead spot survives until there is signal to send it. Proximity alerts use a hysteresis buffer, so a walker standing on the boundary is not alerted over and over, and hazards clear by consensus rather than by decree: three confirmations to mark one gone, and a cooldown per device. All of it resists abuse without asking anyone for an account.
The hosted site is paused and deliberately left inert: the database emptied and closed, sign-in disabled, and hosting switched to a static holding page that says so. Taking something down carefully is its own piece of work.
Next.jsTypeScriptFirebasePWA
- Source on GitHub
- paw-safe.uk

Work

Antinode

Boomer Solitaire

IDS Collection Tracker

PawSafe