Re:Yes meanwhile.. (Score 3, Informative)

Follow these steps to fix the Nexus 7 crawling after the 5.0.2 build of Lollipop. I have done this and the Nexus 7 is now working reasonably well.

Turn off your device.

Press and hold Power and volume down buttons simultaneously until you see a large arrow at the top of your screen.

Press the volume down button repeatedly until you see “Recovery” in the arrow.

Select it by pressing the power button.

You’ll see an android mascot with a red triangle and exclamation mark.

Hold down the power and press the volume up button once and then release the power button.

Press the volume down button repeatedly to select “erase or wipe the cache partition” from the list of options.

Wait for the process to complete and then restart your device.
If successful, you should notice an improvement in your tablet’s performance.