There was no demand for the app or the option, therefore I’ve not prioritized it.
Discussion
Well, maybe it's just me but I had problems uploading a video within a mobile nostr client. So I thought, let's do a workaround and compress + upload the video via Nostr Build Shack and then copy the URL in the note in the Nostr client.
Now I had to use my laptop and upload the video to my own Blossom server and include the link in the note.
So maybe in some cases, it could make sense to have the upload option available :)
Did it have an option to “share” to the client installed on the phone? Also, you could save/upload to nostr.build via browser, using either large upload option or normal one if under 150MiB or so.