The current UI is great but I would like to share some tips (mainly for the ios version) that will make the UI a bit more tablet-friendly while maintaining a desktop-like interface. There is also a tip for a reworked perspective grid and a bug report.
Normal mode
- Selections: the select menu could be moved from the top bar to a popup menu in the select tool similar to the "More..." popup found in the paint tool.
-Transform: edit>transform could become a tool similar to the move one which does not hide the rest of the interface so that different layers could quickly be transformed
-Bucket fill: edit>color fill and edit>fill special could be added to the bucket fill tool as sample modes or to a newly created fill tool.
-Cut/Copy: Cut, copy, paste and so on could be added to the layers panel.
-Masks: as already suggested by other users masks should behave like in photoshop, procreate and affinity photo, where they can be "attached" to a layer.
-Perspective grid: BUG: as of app store version 2.2.1 the grid is bugged and displayed inside an invisible rectangle that scales/rotates with the canvas. FEATURES: 1) add horizontal and vertical lines that get closer as they move to the center but can be moved based on a field of view setting (hard to explain, similar to how the grid changes in a 3d modeling software when the FOV is reduced/increased). 2) Add a spherical perspective grid that mimics the distortion caused by wide-angle camera lens that can also be configured using focal length values. A reference for 1) and 2) could be infinite painter, that offers similar perspective tools (used the app on android long ago, not sure if it's still the same).
Filters: Filters could be added to the layers panel, useful for when (and if) smart filters will be added to Artstudio Pro.
Painting mode
-All of the above.
-All the tools added to the top bar for easier navigation.