If the photos(s) were in an app itself, then you will have to check directly with the creators of that app to see how to recover anything deleted in it, if it is recoverable. If the photo(s) were on the device itself, then try the following...
While there is no guaranty that you can get them back. Deleted does mean deleted. There are a few apps/programs out there that 'may' be able to help you recover the data.
A few of the programs you could try would be... DiskDigger, MobiSaver, Android-Recovery and Tenorshare. They are all data recovery apps/programs. There are many others out there, so check around and see which you would rather try. There is also one called RECUVA, that I have heard is free, which you could try.
One important...