Yes, sure, just copy the link of the image that you want to save, whether the image is on your account or on another account, you must make sure that the account is public so that we can bring the image to you.
You can use IGPANDA on all your devices such as Mac and Windows devices, iPhone and Android phones, iPad and Android tablets.
No, he will not know that the image has been saved, you can use this tool with all privacy.
Unfortunately no, the account must be public in order to be able to save photos from it.
All Instagram photos will be saved in JPG format, it is a good format for saving images in a small size without affecting the resolution.