Is there any recovery software available for ext4?

Take a look at this:

Best tool to recover removed files

Formatted and lost 6 years worth of photo memories.. any way to get this back?

How to recover Ubuntu partition after computer failure?

Where the answers of some other people under those questions may also be helpful for you.

Good luck!

The first thing to do, is to STOP USING THE DISK! Everything that gets written to it runs the risk of overwriting your data. Mount it read only and copy the things you find to a different device.

After that, the tools mentioned by the other contributors are good places to start. Add Magic Rescue, and any raw sector editor to the mix. Magic Rescue is good at finding pictures, videos, zip archives and MS Office files. And the sector editor can be used to find most documents provided you remember some words out of them to use for searching.

Try TestDisk/PhotoRec:

1. CTRL ALT t to open a terminal

2. sudo apt-get install testdisk and type your normal user password

3. sudo photorec

Good luck!

EDIT: take a look at https://help.ubuntu.com/community/DataRecovery too.