I noticed that for most of the apps a user is unable to upload a new file until the system finishes downloading the output file for the previous task, which could be a long operation for large files. It would be very good to be able to do that simultaneously.
Could you, please, give more details about this issue? As far as I know you can deal with the apps simultaneously in several tabs in the browser regardless of the downloading process.
I would like to inform you that we are working on multiple file uploading feature for the most apps limited to 10 files per request. For now you can try Aspose.Words Merger: