Hi,
Does Nexus 7 2013 work with Android 7.1.2 version?
Can I use Solo and Solex applications?
The short answer is YES, as mentioned by Wirednot, Lineage OS 14.1 is the way to go! I just went through this over the last couple days!
I just picked my first drone up (Solo) Thursday after years of drooling over them. The guy I bought it from threw in an old Samsung Galaxy Tab 8.4 which has been revision locked on KitKat 4.x since inception.
My plan was to continue to use the Tablet with the drone with Solex, open solo, etc. The previous owner didn't wipe the tablet (horrible taste in porn btw...lol) so I commenced in wiping it (both figuratively and literally!) and re-configuring it.
Everything worked fine until I tried to use Solex to replace the drone and controller's stock Solo firmware with Open Solo 3.0.0. As part of the documented procedure for upgrading you use the Solex app to attach to a GIT repository and download the copter and controller Open Solo packaged. The process failed at this point with an SSL version error. To cut an already log story short, because of the some OpenSSL vulnerabilities that were patched in later android OS's I was dead in the water (if I wanted to use the very easy method in Solex to install - there are workarounds but this method is SO easy it was worth the time investment!)
Enter Lineage OS 14.1. Straight forward to install and basically gives you "currentish" OS's on older hardware.
In most cases the procedure is simple to replace your old OS. Back your device up (usually making sure your device has every sync option with Google turned on is enough), unlock, root, and install a custom recovery like TWRP and you're ready to install the OS.
If you've never done this (or haven't done it in a while) it can feel daunting but it's super simple and doable! Anyone with moderate tech skills (which seems to be most of this community) can get it done!
Happy hacking!
<D>