Placard: an iOS app for browsing and installing PosterBoard wallpapers

What Placard does that the built-in wallpaper picker does not

iOS ships a wallpaper picker, but it does not give you a catalog of community-made interactive wallpapers, and it does not let you import a packaged wallpaper from outside the system. Placard fills that gap. The README describes it as an iOS app for browsing, creating, installing, and managing custom PosterBoard wallpapers, and the feature list is concrete: search and sort a community catalog, preview entries, download or import local .tendies packages, turn a vertical video of up to 12 seconds into a looping or auto-reversing Lock Screen wallpaper, install directly into PosterBoard, and remove installed custom and featured wallpapers afterwards.

The audience is narrow by design. The requirements section asks for Xcode 26 or later, iOS 26 or later, and a physical device on which bad_query is supported for installation and library management. That last clause is the whole story: the app is aimed at people who already have a device they are willing to experiment on, not at general iPhone users. The repository description pins the target range as iOS 26.0 through 27 beta 4, which tells you the author is tracking a moving OS surface rather than a fixed release.

The .tendies pipeline: fetch, validate, rewrite identifiers, install

The mechanism is documented in the README's How it works section, and it is a four-stage pipeline. Placard fetches the community wallpaper catalog, downloads the selected .tendies package, validates and extracts its PosterBoard descriptors, and assigns fresh identifiers before installation. That identifier rewrite is the interesting part: because two installed wallpapers cannot share the same descriptor identifiers, the app cannot simply copy a package into place. It has to parse the descriptor structure, regenerate the identifiers, and write the result back out.

Access to the target container comes from bad_query, which the README credits as providing the sandbox extension technique used to access PosterBoard data on supported systems. The same access is reused for the read path: Placard uses it to display and remove installed wallpapers, so browsing your installed library and deleting from it run through the same privileged channel as installation.

For a video of your own, the pipeline is the same but the front half is different. Placard generates the required CAML and PosterBoard descriptor structure locally, then installs it through the same pipeline. A SpringBoard refresh powered by NeoSpring finishes the job, which is what makes the new wallpaper visible without a full restart. The architecture is therefore thin: a catalog client, a ZIP and descriptor layer built on ZIPFoundation, a local generator for video input, and a privileged install/read/delete path that everything funnels through.

Building Placard from source and installing your first wallpaper

There is no App Store listing and no Homebrew formula. The README's Building section is the only distribution path, and it is four steps: clone the repository, open placard.xcodeproj in Xcode, select the placard target and choose your own development team under Signing & Capabilities, then build and run on your device. Swift Package Manager resolves ZIPFoundation automatically when the project is opened, so there is no separate dependency install step.

Start by cloning and opening the project:

git clone https://github.com/frs0n/placard.git
cd placard
open placard.xcodeproj

In Xcode, pick the placard target and set your team. The README is explicit that you must choose your own development team under Signing & Capabilities; without that, the build will not produce a runnable app for your device.

Once the app is on a supported physical device, the first real use is the catalog path. Browse or search the community list, preview an entry, and install it. Placard downloads the .tendies package, validates and extracts the descriptors, assigns fresh identifiers, and writes it into PosterBoard, then refreshes SpringBoard through NeoSpring. The README does not document a progress indicator, a failure message, or a rollback path, so treat a successful install as the only observable signal.

The second path is your own footage. Import a vertical video of up to 12 seconds, choose looping or auto-reversing, and Placard builds the CAML and descriptor structure locally before running the same install pipeline. Do not attempt either path on the Simulator: the README states it can be used to browse the catalog and develop the interface, but it cannot install or manage system wallpapers.

Where Placard is the wrong tool

The README carries its own warning, and it is not boilerplate: Placard relies on behavior that is not provided by a public Apple API, compatibility may change between iOS releases, and installing or deleting system wallpaper data carries risk. Read that as three separate failure modes.

First, the install path can break on any iOS update. Nothing in the repository guarantees that bad_query keeps working on a future build, and the app's own description limits the target range to iOS 26.0 through 27 beta 4. If you update your device past that window, you are on your own.

Second, the operations are destructive in a way the app does not appear to mediate. The README does not document rollback, backup, or a restore path for wallpaper data that Placard removes. If deletion goes wrong, the documented surface offers no recovery story.

Third, the Simulator is not a substitute for a device. You can develop the interface against it, but you cannot exercise installation or library management, which means the parts most likely to fail are exactly the parts you cannot test without hardware. If you need a wallpaper tool that works on any iPhone without a development team, or if you are not prepared to lose wallpaper state on a device you care about, Placard is the wrong choice.

Placard compared with Pocket Poster

Placard did not invent this workflow. Its acknowledgements name Pocket Poster by LeminLimez as the original project that inspired Placard's PosterBoard wallpaper workflow and .tendies support. The two share the package format and the general idea of writing descriptors into the PosterBoard container.

The difference is scope. Pocket Poster is the upstream inspiration for the workflow; Placard layers a catalog client, search and sorting, previews, a video-to-wallpaper generator with a 12-second cap and looping or auto-reversing output, and an installed-wallpaper management view on top of it. Placard also splits the privileged access into a separate dependency, bad_query, and the SpringBoard refresh into another, NeoSpring. That is a more modular arrangement, and it is also a longer dependency chain: three upstream projects whose terms and compatibility you inherit. If you only want the original workflow and nothing else, Pocket Poster is the smaller surface. If you want a catalog and a video import path in one app, Placard is the one that has them.

Maintenance cadence, build cost and licensing

The repository is not archived, and the last push was on 2026-08-30. The release list shows v1.6.7 on 2026-08-30, v1.6.6 on 2026-08-21 and v1.6.5 on 2026-08-21, so the project was shipping patch releases within the last month. That is a useful signal for a project tied to beta OS behaviour, because it suggests the author is still reacting to changes rather than having abandoned the codebase.

Upgrade cost is dominated by the toolchain, not the app. Xcode 26 or later is required, and each new iOS release is a fresh compatibility question because the install path rests on undocumented behaviour. Budget for re-testing on a physical device after every OS update; the README offers no compatibility matrix beyond the stated target range.

On licensing, Placard is released under the GNU General Public License v3.0, with the LICENSE file at the repository root. The README adds a caution that some incorporated techniques or source material come from upstream projects, and that the upstream bad_query and NeoSpring repositories may not declare a separate license. If you plan to redistribute a build, that combination is worth checking before you do, since the README itself points you at the upstream terms rather than resolving them. This is not legal advice; read the LICENSE file and the upstream repositories yourself.

Editorial conclusion

Placard is for developers and tinkerers who already build iOS apps from source and accept that the app relies on behaviour Apple does not expose as a public API. It is not for anyone who wants a stable, App Store distributed wallpaper tool, and it is not usable on the Simulator for installation or library management. Before adopting it, verify that your device and iOS build actually support bad_query, check that the upstream bad_query and NeoSpring repositories declare a license you can live with, and confirm your signing team is set on the placard target so the project builds at all.

Frequently asked questions

Official sources

1. frs0n/placard on GitHub
2. Issues
3. License: GPL-3.0
4. README
5. Releases