I got bitten by mosquitoes several times at Cottonwood Lakes after hiking back from Mt Langley in the afternoon via Old Army Pass a few weeks ago. Didn't have repellent so I had to hike faster to try and out pace them.
As for smart phone hiking apps, I use AllTrails on Android. Recommend pro version because you can download maps and keep them on your phone. I got the lifetime version for $99.
If cell phone battery life is a problem, you could bring a power brick with you to recharge it at night, but that is a little more weight.
