Many people are aware that security is important on a computer but most people forget that their smartphone is a full computer as well. And, since you carry that smartphone around with you and can easily lose it, security is as important on your 
phone as it is on your computer.
Here are a few things you can do that will dramatically increase the security of your mobile devices:
- Set a Passcode – Anything is better than nothing, but a short 4-digit pin can be manually cracked in a few short hours by a dedicated hacker. We suggest using a longer passcode and set up Fingerprint or other biometrics to unlock your phone
- Set up Apple’s Find iPhone or Android Device Manager so you can find or erase your device if it is lost or stolen
- Update your phone OS when updates are available – Almost all updates include “security” improvements so it’s important to allow you phone to update.
- Be wary of apps you download. Apple has a slight advantage here in that they vet all Apps on the app store, but malware has been known to get through. Androids require a more skeptical approach to apps – fake banking apps have scammed many people.
- Make sure your phone cloud account (Apple or Google) has a good password. You don’t want someone logging in and grabbing your personal data (email, photos, videos or other files that are backed up online).
For additional details please see:
https://heimdalsecurity.com/blog/smartphone-security-guide-keep-your-phone-data-safe/
https://blog.malwarebytes.com/101/2016/09/top-10-ways-to-secure-your-mobile-phone/