XML File type.

[Mano5JP]

I would like to know if XML is supported to create an app.

or other possible (file extension) to use, currently, I am using excel and google sheet.

thanks.

[WillowMobileSys]

AppSheet apps are web apps.  There are certain places you can inject XML and/or JSON to do certain things within the app.  For example, you can insert JSON in the column notes in a sheet to automatically set certain column properties when the app is first created.

Also, you use the SVG XML tag in Image columns to do some fairly advanced things around images.

BUT, as far as I know, you cannot provide full XML in order to create a complete app.

[Mano5JP]

Aside from excel and google sheet, what else I can use for my data table to create an app?

[WillowMobileSys]

This info is best coming straight from AppSheet. You can find it on the Pricing page. 

https://about.appsheet.com/pricing/

Expand the "Basic App" line to see some supported data sources.  Then look at "Advanced Data" for others.  Databases on almost any platform are also supported.