1. Purchase and install Tweaks for Twitter in the iOS App Store.
2. Open twitter.com in Safari.
3. Press the button in the corner of the address bar.
4. Select "Manage Extensions".
5. Enable Tweaks for Twitter.
6. Press "Done".
7. Select Tweaks for Twitter.
8. Always Allow Tweaks for Twitter on mobile.twitter.com.
The scary warning is just boilerplate text from Apple shown for every Safari extension that can modify webpages. Tweaks for Twitter does not read, use, or share your personal data. The privacy policy has more details about Tweaks for Twitter privacy. See also my blog post The security of Safari extensions for a more detailed explanation of extension permissions.
You only need to enable Tweaks for Twitter once in Safari, and then it will remain enabled permanently. It will remain enabled even after you install new versions of Tweaks for Twitter and iOS. If you ever need to disable Tweaks for Twitter, select Manage Extensions from Safari's address bar.
To change your Tweaks for Twitter preferences, press the extensions button in Safari's address bar and select Tweaks for Twitter. See Tweaks for Twitter Preferences for more information.
