So I got a Nexus 7 2013 tablet recently for my sister. Upgraded it to Android 6.01 (which is the last OTA upgrade available). My sister didn't like it for the reason that there is no Gallery. She was a heavy Gallery user in her earlier tablet. Other than that it worked fine for a few weeks. Yesterday, it went into the circles loop - https://i.pinimg.com/originals/27/03/92/2703922d465e0d968762093b2c1443df.gif - this animation kept going on & on & on - in between it would say updating app 16 of 16 & then again the animation starts again.
I am thinking of doing a factory reset - I assume factory reset would take it back to the 4.x version it came with. Post that I want to upgrade it again but to some version lower than 6.01.
Which is a good stable version before 6.01 which also has the gallery which I can update to?