They are some tools require of your devices patches with rooted access, if you installing Root requirement apps into unroot devices it would not work,
1. GT Recovery
They say this app could recover document, images and media files. I must say Im very impress with this app, yes its works very well on my old Moto G devices both internal and external memory. Go ahead and download it. User interface is good well organize and neat fature indeed, perhaps gonna make full apps review later
2. Undeleter Recover Files dan Data
Scan for recover deleted files on ROOTED devices, so they put like no false hope for unrooted devices. I never this yet. I think its user interface needs to revamp with better contrasity, those grayish isnt friendly with your trouble eyes.
3. Restore Images (Super Easy)
Feature a super easy recovery without need of rooting which is good news for all stock devices.Maybe you should give try and give a comments.
Tips for unroot devices
Each devices has different patch and depends of sofware support, I cant explain how todo, so ask uncle Google with specifically device model, make no mistake or devices will explode, really ! For those people who still cant do it, go sit at the corner and cry alone.