Wipe cache partition HP Slate 7 Beats Special Edition - hard reset method

•  Turn off the tablet

• Use power(1) + vol up(2) to enter the bootloader menu option

select recovery kernel 

• it will enter "no command" screen

Press power button first and vol up button once.

It will enter android system recovery.

• Select wipe cache partition

after the operation, reboot system.

Wipe cache partition Moto G3 - hard reset method

•  Turn off Moto G3 power button(1)

• Use Hard reset button (volume down(2) + power(1)) to enter the bootloader menu

• Select recovery mode by using vol up or down confirm by pressing power

• it will enter "no command" screen, press power button first and then vol up button once

It will enter the android recovery option

Select Wipe cache partition by using vol up or down and confirm by pressing power 

Select Yes to wipe

Reboot

Wipe Cache partition OnePlus 2 - hard reset method

 One can find the info here(https://www.hardreset.info/devices/oneplus/oneplus-2/wipe-cache/). Its replicated here(redundancy is good).

• Turn off OP2 by pressing power(1)

• Use hard reset button(volume down(2) + power) to enter the bootloader menu

It will enter the the boot option (language selection)

in this mode select the language using vol up or down and power to confirm

• select wipe data and cache 

• Select wipe cache and confirm by pressing power

• reboot

How/Why to use Whatsapp on Android tablet without a SIM card - Q1

Before even covering the aforementioned Q1, Q given below are satisfied by Q1..

• What if Mr X don't want whatsapp on mobile 24x7 hogging up battery life, just need it for indoor communication purposes. (or)
• What if touch-screen display is smaller in smartphone, need larger display for better accessibility(or)
• Don't need the whole of contact/address book to be listed in whatsapp.(or)
• Can it be installed on other form factors like laptop or desktop with linux/Win? - Yes, with a virtual full android env available on such machine, whatsapp can be installed

• In a non-smartphone devices like tablet(HP slate 7 beats special edition) which runs android(android version 4.4.2), download the WhatsApp.apk from www.whatsapp.com/android
• Run the prg
• Follow the On screen Instructions .. see below for the various steps involved.

Whatsapp will gather the contact information from the device(skype, email, hangout) Inorder to add mobile number use contact+ app from google store(include the screeshots from the tablet).

ref:http://www.pcnexus.net/2013/11/how-to-install-whatsapp-on-android-tablets.html
http://forums.crackberry.com/blackberry-os-apps-f35/whatsapp-took-all-my-contacts-sent-their-servers-without-asking-me-649363/
https://www.whatsapp.com/faq/en/wp/23741251