If the small thumbnail is visible (some private profiles still show a tiny, low-res version), download it and run a reverse image search via Google Images or TinEye. You might find a public version elsewhere online.
They may request excessive device permissions to collect personal information for identity theft. facebook private profile photo viewer v34 free extra quality
Attempting to use this software or similar tools exposes you to several high-level threats: Phishing Scams If the small thumbnail is visible (some private
Fraudulent. Claims that this software can "bypass restrictions" and allow you to "view and download the profile picture of any locked profile" are technically unfeasible through legitimate means. Attempting to use this software or similar tools
You may be forced into an endless loop of surveys that steal your personal information or charge you hidden fees.
How to post better quality photos to social media? - Facebook