Your phone
is a courthouse.

ProofNest is a mobile evidence documentation app for iOS and Android. Every photo you take is automatically tagged with GPS coordinates, a precise timestamp, and a SHA-256 cryptographic hash — all computed on-device before the file is saved. You can optionally anchor a case to the Bitcoin blockchain via OpenTimestamps, generating a tamper-proof timestamp that anyone can independently verify without trusting ProofNest's servers.

Yes. The free tier lets you create up to 3 cases with 20 photos each, includes GPS tagging, SHA-256 hashing, and basic PDF reports — with no account or credit card required. For unlimited cases and photos, Bitcoin sealing, demand letter templates, Deadline Guardian alerts, and AI-enhanced letters, upgrade to Pro Monthly ($4.99/mo) or Pro Yearly ($24.99/yr, saving 58%).

When you capture a photo, ProofNest immediately computes a SHA-256 hash — a 64-character fingerprint of the file's exact binary content. This hash is stored alongside the image in your on-device database. If anyone later alters the photo by even a single pixel, the hash will no longer match. This mathematical property makes your evidence tamper-evident: you can prove the image hasn't changed since the moment it was taken.

When you seal a case, ProofNest computes a Merkle root — a single hash derived from all your photo hashes — and submits it to the OpenTimestamps public calendar server, which bundles it into a Bitcoin transaction. Once confirmed on-chain, the timestamp is permanent and decentralised. Anyone — a lawyer, judge, or insurer — can independently verify the timestamp using open-source tools, without accessing ProofNest's servers or trusting us. It's a proof of existence that outlives the app.

ProofNest is a documentation tool, not a law firm, and nothing in the app constitutes legal advice. That said, GPS metadata, cryptographic hashes, and blockchain timestamps can strengthen the authenticity and chain-of-custody argument for your evidence. Many small claims cases, landlord-tenant disputes, and insurance claims are resolved without court — and a timestamped, hashed evidence package with a demand letter is often enough to settle the matter. For court use, consult a qualified lawyer in your jurisdiction.

No, in normal use. All photos, GPS data, timestamps, and hashes are stored exclusively in an on-device SQLite database. ProofNest has no backend server and makes no outbound connections unless you explicitly trigger an optional feature: (1) AI demand letters send case text — never photos — to Anthropic's API; (2) blockchain sealing submits a 32-byte hash to the OpenTimestamps calendar server. Neither feature is required, and both are clearly labelled before you use them.

The Demand Letter Engine generates legally-structured demand letters pre-populated with your evidence data — GPS location, photo count, incident date, and demand amount. There are six case-type templates: rental move-in/out, rental car damage, contractor disputes, package delivery damage, purchase disputes, and general legal. Pro Yearly subscribers also get AI-enhanced letters in three tones — Professional, Firm, and Final Notice — generated by Claude (Anthropic's AI) from your case details.

Deadline Guardian automatically calculates the legal filing window for each case type — for example, 30 days for rental deposit disputes, 14 days for carrier damage claims, and 3 days for car rental damage — and sets a countdown from your incident date. It sorts urgent cases to the top of your list and sends push notifications at T-7, T-3, T-1, and day-of. Most disputes are lost not for lack of evidence, but because people miss the filing deadline.

Both tiers include unlimited cases, unlimited photos, Bitcoin blockchain sealing, demand letter templates, Deadline Guardian alerts, documentation checklists, and full PDF reports. Pro Yearly ($24.99/yr) adds AI-enhanced demand letters with three tones (Professional, Firm, Final Notice), locks in your rate for the year, and works out to $2.08/month — saving 58% versus the monthly plan. Pro Yearly is the best choice if you expect to handle more than one significant case per year.

No account or login is ever required. The app works fully offline — you can capture, hash, and document evidence without an internet connection. An internet connection is only needed for two optional features: AI-enhanced demand letters (calls Anthropic's API) and Bitcoin blockchain sealing (calls the OpenTimestamps calendar server). All other functionality, including PDF export, works entirely on-device.

Uninstalling ProofNest permanently removes all cases, photos, GPS records, and hashes stored in the app's private on-device database. There is no cloud backup — which is by design to preserve your privacy. Export any PDF evidence reports or demand letters you need before uninstalling. The one exception: SHA-256 hashes already anchored to the Bitcoin blockchain remain permanently recorded in that public ledger and cannot be removed — but this is a feature, not a limitation, as it preserves your timestamp indefinitely.

A ProofNest photo is tamper-evident, not tamper-proof against an adversary with physical access to your device before capture. What the system guarantees: any modification to a photo after capture — resizing, colour-adjusting, cropping, or pixel-level editing — will produce a different SHA-256 hash that no longer matches the stored value. If the case has been sealed to Bitcoin, even the timestamp cannot be retroactively altered. An opponent cannot credibly claim a photo was taken at a different time or place without invalidating the on-chain record.