It took you about three minutes to spot the unmentioned new feature in the last video. Yes, it was the 7 inventory slots:

I managed to squeeze in the extra slot by moving touchpads further aside and reducing UI scaling a little (about 5% – all the controls will get smaller by this much). But I think it is a price worth paying. Phones are getting bigger and no one is still playing Survivalcraft on a 3.5″ phone. Does such thing even exist any more? In 2011 when Survivalcraft was first released, 3.5″ was mainstream and 4″ was considered huge :-)
But it gets better than that. Why limit ourselves to 7 slots? How about 10:

I always wanted to give you more slots. It makes playing smoother, especially in creative. The insurmountable problem was interoperability between devices with different screen sizes. I know that on a PC you can display 10 slots, and still have tons of space left. But what if someone on a small phone imported a world created on a PC? Where would the extra items go?
For 2.2 I finally figured it out: it doesn’t matter that the extra items will be invisible for someone with a small screen! At least, it doesn’t matter when compared to the grand benefit of having more slots.
Yes, the extra items will be invisible. But you can always make them temporarily visible again by reducing UI scale to “Smallest” (this will always show full 10 slots). You can then move them to other slots and return to your favourite UI scale. How would you know the hidden items are even there? Because there is a warning displayed.
By the way, the hidden slots are “disabled”. They will not pick up items or otherwise get used.
So in 2.2, the number of slots is dynamic. It depends on the size of your screen and on UI scale:

10 slots on a widescreen phone, tablet or a PC
This happens when you import this world on a phone:

7 slots – the minimum number for all devices
You get less slots, and there is a warning displayed: there is something in the hidden slots. I know it’s a little cryptic – but this situation won’t happen all that often. It is a corner case.
One option I am still considering is whether to only show 10 slots in Creative mode. Survival modes would be limited to 7. The only reason for that is to make the game a little harder – 3 extra slots might hold an extra weapon or a tool that will save your life.
Let me know what you think. We need to make the decision before 2.2 is released. Once it’s out – there will be no way back.