Artemis might use a swipe gesture to visually hint at the relation between upvoting and boosting, as shown in the main animation. Here’s a static app mockup with both swipe levels displayed. I’d also imagine that there should be a setting that auto-upvotes posts when boosting.
It looks really nice, but I think it would be a lot more efficient to keep ‘right-swipe’ available to quickly return to the feed from a thread. Makes mobile browsing a lot more streamlined.
I’ve answered this earlier somewhere — these functions coexist. In fact, it’s a standard UI element on iOS, apps like notes or mail utilize the same gesture combination. The difference is that you initiate the swipe from slightly outside the edge to go back, and start somewhere on the screen to open a slide drawer. It’s intuitive to use, and it’s included in apple’s guidelines.