Products
Five product suites
Nelstack groups practical tools into clear products. Open a suite to browse calculators, document formats, stamps, signatures or Whistle.
Pick by the job you have today
- Plan money — rates, EMI, SIP, tax and retirement calculators in Finance.
- Make a bill or receipt — GST invoice, rent receipt, salary slip and 50+ Indian formats.
- Seal or sign a document — Stamp Maker for seals; Online Signature to draw, type or sign a PDF.
- Launch bookmarks fast — Whistle Chrome extension with aliases, fuzzy search and pinned hotkeys.
Finance
Live metal rates and free India-focused calculators for savings, loans, investments, tax and retirement.
Open FinanceBill Generator
Indian bill, invoice and receipt formats with live preview and PDF download.
Open Bill GeneratorStamp Maker
Free online stamp and seal maker — templates, circular text, PNG/SVG and stamp a PDF.
Open Stamp MakerOnline Signature
Draw or type a signature, then sign PDFs and documents in your browser.
Open Online SignatureWhistle - Bookmark Launcher and Manager
Chrome extension for bookmark search — short aliases, fuzzy search, pinned hotkeys, Library and Analytics. Local-first.
Open Whistle
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