Hi @juphi17 ,
Do you want to convert sharepoint list customize form created by PowerApps to be a standalone PowerApps Mobile App?
Sorry for that but there is no way to move your customize form to be a standalone app. Actually, this is not advisable because the customize form communicate with powerapps by the SharePointIntegration control which is not support in standalone Apps.
If you want to save work, just copy(ctrl+c) the controls you want, and paste(ctrl+v) to the screen of PowerApps, it is also very convenient.
Note: Don't forget to add connections, create a gallery to choose item, and change the Items porperty of forms, also you need the submit button to submitform.
Hope this can help.
Best regards,
Sik