I ended up combining this lesson and 4.11 in a slightly different sequence than the lesson suggests.
I had my students pick their app topic and do their brainstorms in lessons 4.8 and 4.9 and that went pretty smoothly. But, when I got to 4.10, I couldn't really understand what the lesson plan was trying to have me do with Code Studio and how the activity guide fit together (especially when it referenced things like a Spanish Helper & Homework Reminder app), especially since the lesson has us use the activity guide after we've been on Code Studio. It also wasn't clear to me how to structure the 90 minute suggested run time - there didn't seem to be any clear breaks in the lesson. I dunno - maybe I missed something in the lesson plan. But anyway - I took a step back and saw that the real outcomes of this lesson seemed to be creating their Navigation Diagram & Paper Prototypes, and being aware of the UI elements in Code Studio.
So, after lesson 4.9, I spent a day having them create their navigation diagrams and paper prototypes without looking at Code Studio yet and without using the provided activity guide. Then, because of some scheduling, I realized it was actually easier for me to do the User Testing as the next lesson (4.11) since it was also unplugged. I tweaked the Activity Guides to make a (Team Activity Guide and a User Activity Guide - I wanted students to have more room to write down their observations, and I wanted to separate the guide into pieces to make it easier for students to handle. I also added an introductory speech modeled after the Code.org video, and I tweaked the reflections tables a little bit to make it more clear how to structure their written feedback (I think one of the tables used to say "what it means", which didn't make sense to me). By the end of the lesson, students have had a chance to reflect on their app and revise it if needed.
After this lesson, I jumped back into 4.10 to show them the Code Studio apps and tweaked the Activity Guide to make it more explicitly about looking for the UI Elements that Code Studio uses - I called it an AppLab UI Scavenger Hunt. After students look through the example apps, they see if they can connect the components to the apps they saw, and then are asked to reflect on their app again to consider which UI elements appear on their screens - and, now knowing that they're restricted by certain UI elements, they may be forced to make even more tweaks to their app. Two chances for revision and reflection in 2 days - once based on user testing, then again based on UI constraints.
Anyway - not sure if this is helpful, but turning 4.10 and 4.11 into a 3-day event worked well for me.