Also, you don't need to restart the app.

Just use Settings -> Other -> Reload Customizations or use Cmd-Shift-R to reload customizations.

On iPad with an external keyboard, you can show the scope at the cursor location by using the keyboard shortcut Control-Shift-P. 

Please check that "source.geo" is the correct scope.

The correct folder is "Local Files/#Textastic/CodeCompletion" (not CodeCompletions)

Can you please give me an example .geo file and tell me which syntax definition you are using?

You can find the built-in code completion files in this GitHub repository:

https://github.com/blach/Textastic-Customization

They are in this folder:

https://github.com/blach/Textastic-Customization/tree/master/CodeCompletion

See https://github.com/blach/Textastic-Customization/tree/master?tab=readme-ov-file#code-completion for information on where to put custom code completion files.

Have a look at the manual to see how you can reload customizations without quitting the app:

https://www.textasticapp.com/v10/manual/customization/custom_syntax_themes_templates.html#reload-customizations

The Mac version of Textastic does not have a built-in web preview. You can however drag the file icon from Textastic's window title bar onto your browser's Dock icon to preview a website.

For Markdown preview, you can use the "Marked 2" app and do the same.

Thank you for your support – I really appreciate it! 

I understand that subscriptions are not for everyone. Adding an option for optional donations is something I'll consider for the future.

Good point, I'll need to think about it.

I believe other editors solve this by displaying only the differing parts of the file path when there are multiple tabs with the same file name. On iPhone this probably won't help much because of the limited room for file names in tabs, but it would help on iPad.

A setting to always show the folder name alongside the file name (e.g., "path/index.php" as you described) should be relatively easy to implement.

In Textastic on macOS, hovering the cursor over a tab shows a tooltip with the full file path. Maybe something similar could be added to iPadOS – though it would only be helpful when using a mouse or trackpad.

Have a look at a theme that has colors for Markdown - for example "Mac Classic": 

https://tmtheme-editor.glitch.me/#!/editor/theme/Mac%20Classic

To give Markdown headers (or a header in any markup language) a different color, it uses the "markup.heading" scope selector.

For lists, you can use "markup.list".

In Textastic, you can press Control-Shift-P to show the scope at the cursor location.