Actually it's the 46th app that initiates in the jump list. But I found that sometimes if you uninstall some apps so you have less than 45, the jump list stays, but not always (a bug).
It's not a bug per say. The design has been like that since WP7.x. 46th app kicks in the indexing and even if you have only 5 apps after that by uninstalling the rest, you will have that jump list on. The only time it reverses back is when you perform a hard reset. Yes, it would be good to have indexing on/off as an option.
this is most definately a bug. Did anyone solve it ? i havent installed any extra apps and it appeared all of a sudden. After it crashed and rebooted. Other forums say it appears after 40 apps some say 45 it is totally random and not a useful addition to the menu system. I already know my alphabet and can work out it starts at A at the top and I am guessing here but Z is at the bottom. To insert 26 extra icons simply slows down the scrolling. mmm 'almost a rant' but I am frustrated with it ! any help ?
46th app kicks it in. If you really want that indexing, keeping adding apps and then uninstall once they appear. Your indexing will stay. If you don't want indexing, don't go beyond 45 apps. I think it's because upto 45 apps it's like 2-3 scrolls away from A to Z, but then it gets to 4th scroll and that is where indexing comes in.
Microsoft will have to "fix" it by allowing indexing on and off. But it works in benefit of the user as it saves another extra swipe. All you do is tap any alphabet it brings up the list of alphabets, select what app alphabet you are after and then you have them all in generally one screen.
So it's more like swipe, tap, tap, tap - to open an app right now.
Without indexing it is - swipe, swipe, swipe, swipe, tap - to open an app.