Mosaic has no accounts and no servers, so there is nothing for me to delete and nothing you need to request. Everything the app keeps is on your device:
- There is no account to close — Mosaic never asks you to sign in.
- Delete the app from your phone: remove it from your iPhone, or uninstall it on Android. This permanently removes every saved collage and every setting, including your layouts, trim points, and export preferences. On Android you can instead keep the app and go to Settings → Apps → Mosaic → Storage → Clear storage (wording varies by phone).
- Delete your exported collages separately, from the Photos app or your gallery app. Anything Mosaic saved lives in your photo library on iPhone, or in the Movies/Mosaic and Pictures/Mosaic folders on Android, rather than inside the app, so it survives deleting the app. Remove them there, then empty Recently Deleted or Trash.
- To withdraw access without deleting the app: on iPhone, go to Settings → Privacy & Security → Photos and change what Mosaic can reach. On Android there is no permission to withdraw, because Mosaic only ever sees the items you pick.
Because the app has no backend, there is no server-side copy of anything — no media, no collages, no settings, no identifiers.