First of all. Luma Touch is great! I've tried many video editors on iOS, and really enjoy using this app.
I have 2 feature requests that would make my life easier.
Blend modes - in addition to adjusting the opacity of layers, the ability to use additive, subtractive, overlay, or other blending modes would be very helpful.
Key framing for each item in a title - Currently you can add shapes and images to titles, and control positions and attributes to create a composition. However, when you keyframe positions or effects, you can only keyframe the entire title with all text and graphic elements locked together. Enabling individual keyframe control of position/effects attributes for each shape, image, and text element in a title would allow the creation of sophisticated motion graphic titles. (which could also be used for templates).
Also, I'm in favor of the requests for size cropping of video clips, and numerical input for values (in addition to the current sliders).
Keep up the great work!