Fastboot normally runs on PC.
What happens if you are like me without a PC? Thanks to Google, with Android,it is possible.
This short simple guide will help you to install fastboot binary and run fastboot commands without a PC.
(This guide assumes your devices are rooted and you have a backup.
Again,assumes you can enter into fastboot mode.
Most devices can do so by powering off your device,press and hold the power button together till the screen displays recovery mode,fastboot mode and reboot.
I won't be held responsible in case of any damages caused to you devices.)
MATERIALS:
Rooted Android OTG supported Phone/Tablet.
Root Browser.
Terminal Emulator.
Fastboot file https://www.dropbox.com/s/35owefwbsvaybke/fastboot?dl=0

METHOD:
Download and put the fastboot file into /system/bin folder with the help of your Root Browser.
Open your Terminal Emulator and enter these codes:
su
mount -o remount,rw/system
chmod 755 /system/bin/fastboot

Note: Hit enter key after typing each code.

Reboot your device.
Open your Terminal Emulator and type the code:
fastboot
If it displays some list of fastboot commands,fastboot is now working on your device.

Fastboot commands are used to communicate with the other connected device is in fastboot mode.

Some few Examples of fastboot commands without the quotes you can use are:

"fastboot devices" (displays connected devices)
"fastboot oem unlock" (unlocks your bootloader)
"fastboot getvar imei" (displays your current imei number"
"fastboot oem writeimei 123456789101112" (overwrites your current imei to new imei '123456789101112')
"fastboot reboot" (reboots your device).

To change your imei ,put your target device into fastboot mode,connect your target device to the OTG Android device and run the fastboot command codes with the help of the terminal emulator.
You must get a successful display.
Type "fastboot reboot" to reboot your device.
Dial *#06# to check your new imei.
Fastboot is a powerful command to be used.

Conclusion:
Just like ADB,thanks to Google for compiling ADB binaries for us to use.Since ADB comes preinstalled on some Android devices,we can run ADB commands just like fastboot commands without PC.
We now see that fastboot is possible to use without PC.
Thanks to Josteink and Chamatht for their support on fastboot binaries to ARM.

ADB file
https://www.dropbox.com/s/b9vkqx9ecideftr/adb?dl=0