Just ScreenTime

A privacy-first Windows screen-time tracker. The current version has no cloud, telemetry, advertising, or network-transfer feature; usage data and diagnostic logs stay on your PC by design.

Get it on the Microsoft Store · Privacy Policy · 日本語は下にあります

What it does

• Three-segment tracking — every second of screen time is recorded as Active (you are interacting), Foreground Idle (window focused, no input), or Background (window open but not focused). Most trackers conflate these; the distinction is what makes the numbers worth looking at.
• Per-app breakdown — today's top apps, with hover details, plus a 7-day stacked chart.
• Day detail — pick any date and see the full per-app record.
• Diary — optional one-line notes through the day, shown next to your usage record.
• Focus tools — exclude non-allowlisted apps from foreground time while background tracking continues, plus a work/break timer.
• Goals and exports — optional local notifications, an opt-in weekly diary digest, and user-initiated CSV/JSON export to a location you choose.
• 100% local — everything is stored in a SQLite file under %LOCALAPPDATA%. There is no account, cloud sync, telemetry, advertising, or app feature that sends this data externally. Small bounded error logs are also kept locally. Upgrading from a pre-rename WinTrack build preserves the original database and a local migration backup; see the Privacy Policy for retention and deletion details.
• Lock-aware — Win+L / auto-lock pauses measurement.
• Light — the tracking agent idles at roughly 20 MB RAM with below-normal priority, polling once per second via cheap Win32 calls.
• Anti-cheat friendly — the agent never reads other processes' memory, never hooks input, and opens process handles with PROCESS_QUERY_LIMITED_INFORMATION only, rate-limited. The full invariants are codified in SECURITY.md.

Install

The supported way to install is the Microsoft Store package — signed, auto-updating, and the supported release channel.

You can also build from source for personal, noncommercial use (see the license).

Building from source

Requirements: Windows 10 19041+, .NET 8 SDK, Visual Studio 2022 (or Build Tools) with the Windows App SDK / WinUI 3 workload.

# Dev loop (unpackaged exe, fast):
dotnet build JustScreenTime.sln -c Debug -p:Platform=x64

# Run the dashboard:
JustScreenTime.UI\bin\x64\Debug\net8.0-windows10.0.19041.0\JustScreenTime.UI.exe

# Isolated, self-contained Store MSIX + .msixupload (Release):
powershell -NoProfile -ExecutionPolicy Bypass -File scripts\build-store-package.ps1

# Sideload: create a self-signed dev cert, sign, install
scripts\create-dev-cert.ps1
scripts\sign-msix.ps1
scripts\install-msix-sideload.ps1

Repository layout

Path	What it is
JustScreenTime.Agent/	Background tracking agent (.NET worker, 1 s poll loop)
JustScreenTime.Core/	Shared data layer — SQLite repositories, Win32 interop
JustScreenTime.UI/	WinUI 3 dashboard + tray icon
docs/	Architecture notes, release runbooks, GitHub Pages source
scripts/	Dev cert, signing, sideload, diagnostics
tools/	DbPeek (DB inspector), MockDataSeeder (screenshot data)

Start with docs/architecture.md for how the agent, database, and UI fit together, and SECURITY.md for the Win32 API rules every change must respect.

License

Source code is available under the PolyForm Noncommercial License 1.0.0: you may read, build, and modify it for personal and other noncommercial purposes. Commercial use and redistribution are not permitted — the official binary is the Microsoft Store package.

If this project is useful to you, you can support it via GitHub Sponsors.

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日本語

Windows のスクリーンタイムをローカルで記録するトラッカーです。現行版には クラウド、テレメトリ、広告、データ外部送信機能がなく、利用データと診断ログは 設計上 PC 内に留まります。

• 3 セグメント計測 — 画面時間を「アクティブ(操作中)」「前面アイドル (表示中だが無操作)」「バックグラウンド」に分けて毎秒記録します
• アプリ別の内訳 — 今日のトップアプリと直近 7 日間の積み上げチャート
• 日別詳細 — 任意の日付のアプリ別記録を表示
• 日記 — 一言メモを使用記録と並べて残せます(任意機能)
• フォーカス支援 — 許可リスト外の前面時間だけを除外 （バックグラウンド計測は継続）するモードと作業／休憩タイマー
• 目標・エクスポート — ローカル通知、明示的に有効化する週次ダイジェスト、ユーザー操作による CSV/JSON 保存
• 100% ローカル — %LOCALAPPDATA% 配下の SQLite ファイルに保存。 アカウント、クラウド同期、テレメトリ、広告、外部送信機能なし。例外時の 小さな診断ログもローカルに保持します。旧 WinTrack 版から移行する場合だけ、 元DBとローカル移行バックアップを保持します（詳細はプライバシーポリシー）
• ロック検知 — Win+L や自動ロック中は記録しません
• 軽量 — 常駐エージェントは約 20 MB RAM、BelowNormal 優先度
• アンチチート配慮 — 他プロセスのメモリ読み取り・フックは一切行いません。 詳細は SECURITY.md

インストールは Microsoft Store 版 を推奨します(署名済み・自動更新)。ソースからのビルドは個人利用・非商用の 範囲で可能です(ライセンスは PolyForm Noncommercial 1.0.0 — 商用利用と再配布 は不可)。

プロジェクトの支援は GitHub Sponsors から。