Castiel
castiel.dmkilab.com
Spec sheet
- Headquarters
- Dublin, IrelandRead 19 Oct 2026 · castiel.dmkilab.com
- Accessibility
- The app supports keyboard operation and native desktop screen-reader systems for Windows, macOS, and Linux.Read 14 Nov 2026 · castiel.dmkilab.com
- AI providers
- Programming+ can use user-supplied Anthropic, OpenAI, Qwen, or DeepSeek providers; Castiel has no built-in AI.Read 14 Nov 2026 · castiel.dmkilab.com
- API key security
- AI provider keys are held in the operating system's secure store and are not shared with Castiel's authors.Read 14 Nov 2026 · castiel.dmkilab.com
- Calculator modes
- Castiel combines six calculator modes with a shared computation engine and editable paper tape.Read 14 Nov 2026 · castiel.dmkilab.com
- Connectors
- Optional connectors support live currency rates, custom web endpoints, AI providers, and receipt printers.Read 14 Nov 2026 · castiel.dmkilab.com
- Engineer features
- Engineer mode includes computer algebra, matrices, units, constants, numerical methods, and plotting.Read 14 Nov 2026 · castiel.dmkilab.com
- Financial tools
- Financial mode covers time value of money, cash flow, amortization, bonds, depreciation, breakeven, and interest conversion.Read 14 Nov 2026 · castiel.dmkilab.com
- Paper tape
- The editable paper tape is shared across modes and supports revising earlier calculations.Read 14 Nov 2026 · castiel.dmkilab.com
- Platform availability
- The opened download page lists Windows and Linux as available, Android in open testing, and macOS and iOS as coming soon.Read 14 Nov 2026 · castiel.dmkilab.com
- Privacy and data
- Calculations, saved tapes, and settings are stored locally, and connectors are optional; no outside connections occur if none are configured.Read 14 Nov 2026 · castiel.dmkilab.com
- School features
- School mode includes graphing, statistics, equations, spreadsheets, and other learning tools.Read 14 Nov 2026 · castiel.dmkilab.com
Plans and prices
Free tier Free No time limit for Simple and School; advanced modes limited to about 30 minutes per session. Simple and School · paper tape · advanced modes about 30 minutes/session Read 14 Nov 2026 · castiel.dmkilab.com
Linux Free Free in full; no session timer. Linux · every mode · Debian, Flatpak, AppImage, tarball Read 14 Nov 2026 · castiel.dmkilab.com
Windows full version $2, paid once One-time purchase; removes the session limit on advanced modes. Windows · all modes · editable tape Read 14 Nov 2026 · castiel.dmkilab.com
Where Specifiction places it
- Scientific Calculator Apps#4 of 328.2