Sumvision Cyclone Voyager 7" / PiPO S1 rooted Android 4.2.2 firmware v.1.2 revision January 2014

First you have to download the Sumvision Cyclone Voyager 7" / PiPO S1 rooted Android 4.2.2 firmware v.1.2 revision January 2014 from here, here or from here. Next, download the Rockchip Batch Tool v1.7 from here.

Now put the Pipo S1 tablet into 'firmware update mode', run the Rockchip Batch Tool v1.7, select the update.img file and press 'Restore' button. Wait for 4-5 minutes and that's it. First boot takes longer, about 5 minutes, so please be patient.

Custom ROM features:
- Android Jelly bean 4.2.2
- Kernel 3.0.36+ 
- root with latest SuperSU version 1.91 (free version)
- removed most Chinese and unnecessary applications
- Google Play Store fixes so more application are visible/compatible
- updated busybox v1.21.0.git (2012-11-29)
- Unix like init.d boot scripts support, more details on init.d scripts here
- changed permissions on external sdcard to allow write access
- increased space for applications (/data partition) to 3 GB
- disabled OTA updates 
- kernel modules (cifs, tun, lan, serial, xpad) compiled by Oma & Crew RKTablets
- NEW!  optional ClockworkMod (CWM) Recovery easy install package
- about 14.000 points in Antutu Benchmark.
- HDMI is working perfectly 
- Build number: rk30sdk-eng 4.2.2 JDQ39 eng.root20140111.123608 test-keys

Another way to install CWM 6.0.31

To install the CWM 6.0.2.7 please follow the update steps from this post. Then download CWM 6.0.3.1 from here or from here and copy it as it is on a micro SD card, install Quick Boot free from Play store, reboot into recovery, then choose 'install zip from sd card' and apply the new CWM zip file from your card. Enjoy CWM 6.0.3.1 on your tablet!

BTW, don't forget to calibrate your battery using this tutorial.

Here is the original post.
Credits go to Kasty for rooted version and Cristian Czinege for mirror link.