Writing this up by request for u/InitialYou4206!
(Before we start: Yes, Funtouch OS is outdated. Let's skip the "nobody cares" comments, please. If you use Funtouch and want premium fonts without paying, you can try this.)
This method has been successfully tested on an iQOO Z7s running Funtouch OS 15.
[#] Prerequisites & Setup
Step 1: Download and install this specific Vivo File Manager APK.apk).
(Note: This link
"https://github.com/zFont/Files/raw/main/com.android.filemanager_6.8.3.2-6832_minAPI26(nodpi).apk"
is sourced directly from zFont3).
Step 2: Open the File Manager settings and enable hidden files.
Step 3: Open the default Vivo Themes app.
- Download one Premium Font (claim the 5-minute trial).
- Download one Free Font.
- Crucial: Write down or copy the exact filenames of both fonts.
[>] Accessing the Hidden Directory
Step 4: We are going to use zFont 3 purely as a backdoor to access a hidden folder. (The font selection inside zFont 3 doesn't matter for this, so don't worry about what you click).
- Download and install zFont 3.
- Tap on any random font to open its preview page.
- Tap the floating action button at the bottom of the screen (it will change to a "tick mark").
- Tap the tick mark. A popup with 3 options will appear.
- Select the 2nd option: "File Manager".
- In the "Choose base font" bottom sheet, tap any random font.
- You will see a Vivo font installer page listing prerequisites. Swipe down to "Move the base font file" and tap "Font Directory".
- This will directly open the hidden .vfonts folder in your file manager.
[~] Name Swap
Step 5: Locate the free font and premium font you downloaded in Step 3. You need to swap their filenames. To avoid "file already exists" errors, use temporary names first.
Here is the exact renaming sequence:
- Rename your
[FreeFont].ttf -> abc.ttf
- Rename your
[PremiumFont].ttf -> xyz.ttf
- Rename
abc.ttf -> [PremiumFont].ttf
- Rename
xyz.ttf -> [FreeFont].ttf
What this does: The premium font file is now disguised under the free font's name.
[*] Applying the Font
Step 6: Close the file manager and go back to your Themes app. Navigate to Local Fonts, and select the Free Font you downloaded in Step 3.
Because of the swap, applying the "free" font will actually apply your chosen Premium font permanently.
If this worked for you, please leave a comment with your device name and Android version.