On the rx, sometimes people recommend taking one or two doses at home to find out whether you have any bad side-effects. I've only experience the tingling finger-tips once.
Bugs: Yep, I've seen them go after others and hardly bother me. My daughter for one -- drove her mad.
Mapping app: You don't really need one on that trip. But it's still fun to have, and see exactly where you are during the trip. I have an InReach, so use Earthmate on the iphone ($30/yr without InReach subscription). Unfortunately, my i7 had serious battery problems on a 4-day trip. Airplane mode, shut down ALL apps AND Bluetooth, and it had almost nothing left on day 4. Turned it on only every several hours. This may be an iphone battery issue, though.
Bob Pickering has an Android, using a different App -- Hope he chimes in and names it here. He had 67% battery left after 4 days.
