50 of the Best Travel Apps.
https://www.timeout.com/city-guides/travel/50-best-travel-apps/

TSA PreCheck Application
https://www.tsa.gov/precheck

TSA PreCheck Screening Process
https://www.tsa.gov/travel/security-screening 

TSA Procedures for Disabilities and Medical Conditions
https://www.tsa.gov/travel/special-procedures 

TSA Rules on Traveling with Children
https://www.tsa.gov/travel/special-procedures/traveling-children 

You may file a claim if you are injured or your property is lost or damaged during the screening process.
https://www.tsa.gov/travel/passenger-support/claims

TSA Travel Tips
https://www.tsa.gov/travel/travel-tips

Airline listing with baggage restrictions for each airline.
https://www.seatguru.com/browseairlines/browseairlines.php

Using your phone while traveling abroad. How to use your phone internationally.

https://www.verizon.com/info/technology/international-cell-phone-use/

Trainline: Europe's biggest train and coach app.

https://www.thetrainline.com/en-us/trains/europe