What are some alternatives?
When comparing Keikai and Publisheet, you can also consider the following products
EtherCalc - EtherCalc is a web spreadsheet.
SpreadsheetWEB - SpreadsheetWEB is a no-code platform that helps businesses translate their collective Microsoft Excel expertise into robust web applications with limited or no reliance on IT resources.
LibreOffice - Calc - LibreOffice Calc is the spreadsheet program you've always needed. A fork of OpenOffice.
SpreadsheetConverter.com - Use online spreadsheets, smart forms and beautiful charts in your blog or website. Put your booking and order forms online. Show live charts. Change any cell and the online spreadsheet or live chart immediately updates itself.
Microsoft Office Excel - Microsoft Office Excel is a commercial spreadsheet application.
Sheety - Turn any Google sheet into an API instantly, for free. Power websites, apps, or whatever you like, all from a spreadsheet. Changes to your spreadsheet update your API in realtime. Neat