Drop in your photos, add your handle, and click where you want it to sit. Everything happens on your device, so your photos are never uploaded anywhere.
On your phone, saving opens the share menu. Tap "Save Image" (or "Save Images") to put them in your Photos.
Saved photos have their location and camera details removed.
iPhone tip: if HEIC photos won't open here, set Camera > Formats to "Most Compatible", or share them as JPEG first.