Someone asked about typing on a tablet with a trackball. Until dwell clicking gets the bugs worked out (Therapy Box’s Mouse Trak) or doesn’t require specialized purchases (Unique Perspectives’ Dwell Click), your best bet is something like a switch-adapted L-trac or a trackball in conjunction with a click switch (for which you’d possibly need a hub port). For Android, anyway–I think iPads are ahead in accessibility options.
While it’s possible to use a trackball with a tablet, one drawback is that (depending on the tablet) it can’t be used while the tablet is charging. Bluetooth connection would be ideal, but despite several wireless models, trackballs don’t appear to be common enough to warrant Bluetooth versions. So when Kensington released a Bluetooth-capable version of the Expert I already use, I tried it–and promptly sent it back.
To be fair, it worked when it worked, but that was only for about ten minutes on both my laptop and a Galaxy Tab 4. To pair it properly, you need to install TrackballWorks on your PC. You can’t install it on Android, but I got lucky (once) and it was recognized anyway… until the connection dropped and I couldn’t get it back on either the tablet or PC despite repeated reinstallments. Perhaps that was a fluke. But here’s the major problem: To pair it, you have to hold down all four trackball buttons at once. This was very awkward for me–especially since I had to do that A LOT trying to reconnect. It got painful. Considering that Kensington once mentioned how their wired Expert can benefit people with hand problems, this is a bit disappointing. A less agile pairing method would be great.