The main reason for Flashing Custom Recovery
- Install Custom Roms
-To perform a Nandroid Backup
-To Flash Zip files such as SusperSU.zip, Custom ROM.zip etc
-Perform Factory Reset and lots more
Recovery image can be installed both for rooted or non-rooted users. You can install recovery image using Pc with MTK droid tools, SP Flash tool, Odin etc. It can be done for both roooted and non-rooted users.
It can also be done with your android device but that requires root access to flash the recovery image.
Io boot your phone into recovery image, it varies with the phone brand some devices you will hold power button and volume up, for some power button and volume down while others maybe power button and volume up(or down) and Home menu key[Mostly for Samsung devices]
Top Three Application Used To Flash Recovery Without PC
1. Mobile Uncle Tools
1. Download Mobileuncle Tools.apk
2. Install and Open it and grant root permission.
3. Download the CWM orTWRP recovery file image for your phone and move it to the roort of your SDcard(i.e outside your Sdcard not inside any folder)
4. Go back to Mobileuncle Tools and Click on "RECOVERY UPDATE"
5. Navigate to the recovery.img file you have earlier downloaded and select it.
6. It will install it and ask If you will like to reboot your phone into recovery mode.
You have successfully flashed recovery image into your device
2.
Flashify
Flashify can be used to flash custom recovery into any android device.
1. Download Flashify.apk and Install it
2. Download the CWM orTWRP recovery file image for your phone and move it to the roort of your SDcard(i.e outside your Sdcard not inside any folder)
3. Open Flashify and Grant Root permission and Click on Recovery image
4. A pop up will appear and navigate to where the recovery image is.
5. Tap on the recovery.img file and tap Yup.
You have successfully flashed Custom Recovery image into your device
Flashify
3. 
Rashr
Rashr is the third best in my list from my experience. It's quite easy to use.
How To flash Recobery Image with Rashr
1. Downnload Rashr.apk or from playstore and install it.
2. Download the CWM orTWRP recovery file image for your phone and move it to the roort of your SDcard(i.e outside your Sdcard not inside any folder)
3. Open Rashr and grant root permission.
4. It will ask you to backup your stock recovery image, you can ignore it If you don't want to( i advise you back it up incase you want to flash back your stock recovery image)
5. You will see CWM Recovery, TWRP Recovery, PHilz Recovery or Recovery from Storage
7. Navigate to where the recovery image and click on it
8. It will ask you to boot in recovery image and click ok.
You have successfully flashed your recovery image into your android device.
Other application that can be used to flash recovery image include ROM Manager and TWRP manager.
Note: You phone must be rooted to flash recovery image without using PC
If you have any issue flashing witha ny of the applications listed above, notify in the comment section.
