Nexus 7 Slows Down on Android Lollipop

Here's a simple fix that worked for me:

Clearing your troubled tablet’s cache will reportedly resolve the issue and it’s pretty easy to do. If you’re up for the challenge, just follow these easy steps:

• 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.

Source: Mark Hern (2014) at http://9to5google.com/2014/11/19/2012-edition-nexus-7-running-slow-after-installing-lollipop-this-might-help/

 and:

These steps are all easy to do and reversible.
Settings > About tablet > tap on the “Build number” entry seven times, which will unlock “Developer Options”.
Settings > Developer options > Set WINDOW ANIMATION SCALE, TRANSITION ANIMATION SCALE and ANIMATOR DURATION SCALE all to ANIMATION OFF
Settings > Developer Options > Background process limit > at most 3 processes
My tablet now goes fast enough to keep me sane until it is (hopefully) fixed with updates.

Source: Jason Molesky (2014) as comment to the above source.

I hope this works the same for you.

Best regards,

Jong San Pedro, M.T.M.
Manila, Philippines