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CALCONIC_ - Build & add interactive calculators to your website! Choose from more than 50 premade calculators or build your own from scratch. No coding required. Free plan available. Zapier Integration. Publish Anywhere.
Sheetgo - Connect spreadsheets. Automate your work.
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Aspose.Cells for Cloud - Aspose.Cells for Cloud is a REST based API for processing spreadsheets in the cloud.
uCalc - uCalc is a universal builder of forms and calculators.