The apps are graded on:
Transparency
Privacy policy easy to find
Clear data explanation
Data sharing Explained
Purpose Explained
Clear language
Security
Uses Encryption
Offers 2FA
Has a good security track record
Regular Updates
No major unresolved breaches
User Control
Can users delete their data
Can manage permissions
Can opt out of tracking
Can download data
Settings easy to access
Responsible Sharing
Limited third-party sharing
Clear explanation of partners
No excessive data collection
Ethical use of data
Transparent about ads/tracking
The points are based on research into the apps security. Each part of the section goes up to 5 with 5 being the best and 1 being the worst. The points for each section totals up to 25 the higher the score the more trustworthy they are.