Follow the steps -:
1) Firstly install dumpster app [ Click here ]
2) open it normally
3) If you want to know how this app work then click on " Show me how " otherwise click on "Skip"
4) That's It, you are ready now if you delete anything then the fill will be automatically save on dumpster app
5) If you want To Get the deleted file back simply Open dumpster app
6) Search Your file and click on 'Restore'