Ze*****
I built QuestSync, an Android app to auto sync folders & back up photos to Google Drive, Dropbox, OneDrive, pCloud, MEGA, Internxt, NAS/SMB and 25+ clouds. Two-way sync, mirror, and cloud-to-cloud transfer (e.g. Google Drive to Dropbox) with no PC. Transfers resume after restarts. InstaSend shares files over Wi-Fi via QR code, and the receiver needs no app. No servers of ours; logins stay encrypted on your phone. Free tier, cheap Pro. Feedback welcome!