I have a sharepoint custom list which have 5 site columns, and this list with the same name and same column names is added to 10++ site collections. now i have customized the create/edit/view list forms for one list using a single power app. so my question is; since i have the same list (same columns names) added inside the 10 site collections, so can i create a single power app and reference it from the 10 lists inside 10 separate site collections? or i should create 10 separate power apps for the 10 lists and manage them separately ?
If you created your Power App by selecting the Customize SharePoint List forms option in your SharePoint list, that Power App is only for that list and can't be used for any other list.
You would have to customize the list forms for each individual list.
@JR-BejeweledOneyes i created my Power App by selecting the Customize SharePoint List forms option.. is there other option for customizing the list forms? and if the answer is Yes then will this allow me to re-use the same power app on multiple sites?
No, the built in option is the only available option for customizing the list forms.