yeah, the app.db should contain positioning. the default icons, if that's what you mean, are listed in one of the tables as well as the game/app names (in the same table). there's also another table with all of the PARAM.SFO credentials. I personally wouldn't mess with that one unless you know what you're doing as the values and keys can be complicated. since extrememodding is mostly about cosmetic changes, my guess is that that's not been changed. I don't have my app.db with me, and I've never modded the ps4 one, but I have modded the vita's. it goes by page and position which the ps4 may go by as well. however, I'm not sure how it's done on the ps4. with the vita, it uses a page (screen that the content is on including bubbles) and position (from 0-9 iirc) within each page (1-10 or 20-30+ if using bubbles). I hope that makes sense. you'll know what's going on by comparing the app.db with what's on the screen.