DroRef

A free reference board for artists on Android — opens and saves PureRef .pur files.

⬇️ Download · 📸 Screenshots · ✨ Features · 🛠️ Build

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📸 Screenshots

Board

Light theme

Floating over another app

Slideshow

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💡 What is DroRef?

DroRef helps artists gather their reference images on one infinite board on a phone or tablet, without a PC and without losing the boards they already made in PureRef. It is free, open source, works offline and contains no ads or trackers.

Boards move between the two apps as .pur files: File → Open .pur, Save, Save as .pur (from PureRef 2, save with Save as → Legacy PureRef scene first).

DroRef is an independent app written from scratch and is not affiliated with PureRef or Idyllic Pixel. On PC, use the original: https://www.pureref.com · 🌐 Website: https://iurika-n-t-r.github.io/DroRef/

👥 Who is it for?

• 🎨 Illustrators & painters who keep moodboards and references next to their drawing app
• 🖥️ PureRef users who want their .pur boards on Android
• ⌨️ Tablet + keyboard / Chromebook users — same shortcuts and mouse controls as PureRef

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✨ Features

	Feature	Description
🖼️	Infinite board	Images, videos, GIFs, notes, drawings — pan, zoom, rotate, scale, group
📂	PureRef compatible	Open and save .pur files
🪟	Always on top	Float the board over your drawing app, with opacity and click-through for tracing
🔗	Nodes & connections	Link items with curved arrows that follow them
📥	Drag & drop	From the gallery, browser or files in split screen — and back out
⌨️	Keyboard & mouse	PureRef's shortcuts, command palette, in-app guide (Ctrl+H)
🗂️	My scenes	Every board as a preview, in folders
🔒	Private by design	No account, no tracking, everything stays on the device

📖 Full guide — gestures, tools, keyboard & mouse

• The canvas fills the screen (dot background by default; grid or plain in the menu, under View; a center cross and a frame around the content too). Round buttons: menu and scene name top-left, undo, redo and focus mode top-right, add bottom-right (a short list: images, paste, note, node, draw).
• A rail of tools bottom-left: select, hand (drags and pinches only move the view, nothing moves by accident), connect, draw, and lock: images / videos / drawings, or notes / nodes / connections, can be locked so only the other layer is editable.
• The menu is a panel of icon tiles grouped by purpose (Add, Board, File, View); search, settings and about sit in its header.
• Add images and videos from the gallery, paste them, paste a link, use Share → DroRef, or drag and drop them from another app (gallery, browser, files) in split screen: they land where you drop them.
• To drag an image out to another app, select it, then long-press it again and drag.
• Drag empty space to pan, pinch to zoom, double-tap to focus.
• Tap to select. Drag to move; pinch or twist with two fingers to scale and rotate.
• Long-press an item to add it to the selection. Long-press empty space and drag to select a rectangle; release without dragging for the canvas panel.
• What's selected gets corner handles (drag to scale from the opposite corner), a rotate handle on the right (sticks at 45°), its size on the board underneath, and a short toolbar floating just above it (long-press an icon to see its name): info, rotate (90° / 180° / 270° / reset), size (100 % / ×2 / ×½), more and delete. "More" lists everything else in one scrolling list, by section: Transform, Arrange, Align, Normalize, Layers & groups, Item (duplicate, color label, web link, copy, cut, export…).
• Nodes and connections: with connect, drag from one item to another to link them with a curved arrow that follows both; let go on empty space to create a new node there. Tap a connection to reverse it, put arrows at both ends, recolor or delete it. Save as .pur turns connections into drawings, since PureRef has none.
• My scenes (tap the scene name, or Ctrl+Alt+L) shows every scene as a preview; long-press one to rename it or move it into a folder. Ctrl+Shift+L jumps back to the previous scene.
• Always on top floats the board over your drawing app. Its bar has opacity, transparent-to-touch (for tracing), background off (only the images float), and a pin to show it only over one app (Android asks once for usage access).

Everything PureRef has, and what's done here: FEATURES.md

⌨️ Keyboard and mouse

With a tablet keyboard cover, a Bluetooth keyboard and mouse, or a Chromebook, DroRef works like PureRef on a PC: same default shortcuts, same mouse controls. Ctrl+H (or the keyboard button in the menu) opens a short guide in the app; Meta+/ lists every shortcut. The first time a keyboard is connected, DroRef points to the guide.

Mouse
Left-drag on empty space	Select (Shift adds to the selection)
Left-click / drag an item	Select / move it (Shift-click adds, Shift-drag moves in a straight line)
Ctrl-drag	Rotate (Ctrl+Shift: 45° steps)
Ctrl+Alt-drag	Scale
Middle-, right- or Alt-drag	Pan
Right-click	Menu for the item, or the canvas
Wheel	Zoom
Touchpad	Two-finger swipe pans, pinch zooms, Ctrl + swipe zooms

Keys
Ctrl+Z / Ctrl+Shift+Z	Undo / redo
Ctrl+C / X / V, Ctrl+D, Del	Copy / cut / paste, duplicate, delete
Ctrl+I, Ctrl+N, Ctrl+Shift+D	Add images, note, draw
Space, Ctrl+Space, ← →	Focus selection, focus canvas, previous / next
Ctrl+P, Ctrl+Alt+N / A / O / D / R	Arrange optimal, by name / addition / order / path / randomly
Ctrl+arrows, Ctrl+Alt+arrows	Align, normalize
Alt+Shift+H / V, Ctrl+Shift+T	Flip, reset transform
Ctrl+G / Ctrl+Shift+G, P, ↑ ↓	Group / ungroup, parent, front / back
Ctrl+K, Ctrl+Alt+L, Ctrl+Shift+L	New scene, my scenes, previous scene
Ctrl+S / Ctrl+Shift+S, Ctrl+L	Save / save as .pur, open .pur
Ctrl+Shift+P	Command palette

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⬇️ Download

 

🟢 Recommended: with iurikaFlows (automatic updates)

1. Install iurikaFlows → download here.
2. Open it and find DroRef in Découvrir.
3. Tap Install. Future updates arrive automatically. ✅

🔵 Manual install (APK)

1. Go to the latest release.
2. Under Assets, download the file ending in .apk.
3. Open it on your phone. If Android asks, allow "Install unknown apps" for your browser/file manager.
4. Tap Install. Done! 🎉

Also ready for F-Droid: the store listing lives in fastlane/metadata/android/.

❓ Why isn't it on the Play Store?

DroRef is an independent, free project. Instead of the Play Store, it is distributed through GitHub Releases and iurikaFlows, a small open-source store that keeps all my apps up to date. The APKs are built from this public source code — you can check everything.

🛡️ Is it safe? Android says "unknown source"

This warning appears for every app installed outside the Play Store. The code is 100% public in this repository, and each release is signed with the same key, so Android will refuse any modified version.

Requirements: Android 8.0+ · ~0.5 MB

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🛠️ Build from source

For developers — click to expand

Prerequisites: Android Studio (latest) or the Android SDK (platform 36) · JDK 17–21

git clone https://github.com/Iurika-N-T-R/DroRef.git
cd DroRef
./gradlew assembleDebug

The APK is generated in app/build/outputs/apk/debug/.

Signed release: ./gradlew assembleRelease signs the APK only if a git-ignored keystore.properties (storeFile, storePassword, keyAlias, keyPassword) sits at the project root; otherwise it comes out unsigned.

Test the .pur reader and writer:

./gradlew testDebugUnitTest -PpurDir=/tmp/pur

That writes kt_edit.pur into the folder. Check it with real PureRef: PureRef -c 'load;/tmp/pur/kt_edit.pur' -c 'exportScene;/tmp/pur/out.png' -c exit

• ./gradlew bundleRelease → signed AAB in app/build/outputs/bundle/release/. Unsigned builds are what F-Droid expects (it signs with its own key).
• Launcher icon: art/icon.png → python3 -I tools/icon.py regenerates every size.
• Translations: one table, tools/strings.py → python3 tools/strings.py regenerates every strings.xml.
• tools/ui.py drives an emulator for quick UI checks (tap by label, screenshot).
• Everything PureRef has, and what's done here: FEATURES.md

Project structure

DroRef/
├── app/            # Android application
├── art/            # source of the launcher icon
├── docs/           # website (GitHub Pages) + screenshots
├── fastlane/       # F-Droid store listing
├── third_party/    # licenses of bundled assets
└── tools/          # icon, strings and UI-test scripts

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🤝 Contributing

Ideas, bugs, translations — all contributions are welcome!

• 🐛 Found a bug? → Open an issue
• 💡 Have an idea? → Open an issue and describe it
• ⭐ Like it? → A star on this repo helps other people find it!
• ☕ Want to support the work? → Buy me a coffee

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🧩 More apps by Iurika-N-T-R

App	Description
iurikaFlows	My open-source app store — installs and updates all my apps
OnlyFlows	Offline-first task & project manager with LAN sync
ColorFlows	Color harmonies, palettes from pictures, painter's shading sphere
galleryFlows	Gallery that browses your real folder tree
vidéoFlows	Your own videos in a vertical swipe feed
RandomFlows	Randomizer & decision maker on your own lists
Brush Converter	Photoshop .abr brushes → Infinite Painter .przp, in the browser

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🙏 Credits

• .pur format: ported from FyorDev/PureRef-format (MIT)
• Video loops idea: lettucegoblin/AnimRef (MIT)
• Icons: Lucide (ISC, see third_party/LUCIDE_LICENSE.txt); tools/icons.py converts them

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📄 Released under the MIT License

Made with ❤️ by Iurika-N-T-R

_{If DroRef is useful to you, consider giving it a ⭐ — it really helps!}