A few months ago I cracked my Google/Asus Nexus 7 screen/digitizer and the touch is no longer working on 90% of the screen. Only a small part in one corner still detects touch. The display still works fine otherwise, but it was essentially useless.
I looked into several ways to try and make the Nexus 7 usable again, including:
1. Tried to find an app that might all me to use the small working touch area to control apps (e.g. keyboard apps that can be controlled without needing the entire screen);
2. Tried to use MonkeyRunner to script apps to control them. However, this required me to accept the PC in USB debugging mode, which I couldn't do without being able to tap on the "OK" button...
3. Tried to find a cheap replacement screen/digitizer on eBay but I wasn't willing to spend more than EUR60.
4. Seriously considered getting a new Nexus 7 2013 model.
Eventually I've found an amazingly simple solution to make it fully usable again: A cheap OTG cable (Micro USB male to USB female), which allows me to plug my Logitech K260 wireless keyboard & mouse into the Nexus 7.
It's not exactly a tablet anymore, but compared to a broken piece of unused electronics lying in my drawer, this is great! The Nexus 7 with keyboard and mouse is now basically like a small Android laptop. Still perfect for surfing the web etc. I'm extremely happy that for only 3 GBP I've now got a working device again.