I'm not a big fan of "crafting" in RPGs.  I've seen way too much abuse of crafting rules over the years.  Unfortunately, in some genres, such as cyberpunk, crafting is needed in certain areas.  There are many cyberpunk stories where a character has written their own software.

Looking at the Hacking rules, "Writing Apps" in particular, I can think of a few of my current players that will be trying to abuse the heck out of them.  The main area of abuse is the fact that it doesn't cost anything but time to write an App.  And time is the least precious resource in an RPG.  My main concern are the players whose characters will spend their time between adventures trying to generate as many die-rolls as they can.  With VR compression, they can effectively spend "years" working on a complex Apps without any real worry about the actual difficulty.  
As I said, time is the cheapest thing in an RPG as players generally don't delve into the day-to-day activities.  When I ran Shadowrun (5th ed), which includes downtime activities, I had to put limits on how much time characters could spend on them.  Before I did, the players treated their characters as if they were Type-A personalities that were all work/no play complete with aides that took care things like cooking, cleaning, weapon maintenance, socializing, etc....

I'm not really looking forward to having my players' characters spending every single day of downtime between adventures "working on Apps" as they keep trying to roll high to create Apps for "free" that are better than the examples in the book.  Why buy an App when you can write a better one for free?

(Also as a Software Engineer, I'm highly amused by the idea that an App can be written in 24 hours.  But, I'm sure folks with military experience as just as amused by combat systems in RPGs.  I'm also talking about a game involving fictional technology using a game system the reflects popular entertainment and not the real-world,   If Fitz, from Agents of SHIELD, can come up with a cloaking spy drone while researching alien portal technology in his spare time, I can accept that PC Hackers in IZ can write Apps quickly.)

So I'm pondering making a few small adjustments to keep things interesting.

1) State of the Art.  State of the Art (SOTA) is always changing.  That attack program that worked well last week might not work next week as the exploits that it used have been patched. (Purchased Apps don't have this problem as it is assumed that they are being maintained by the seller)

When an Apps is created, the time ladder is consulted.  Starting at "A Day" shift up one rung for each shift of success.  Once this time passes, the App gains the Aspect "Outdated".  The Aspect can be removed with another Hacking roll, starting at Mediocre (+0) + the number of AMS used by the App (base time 24 hours). Number of shifts generated gives the new SOTA time (starting again at "A Day").

2) App Aspects.
In order to generate more shifts of success, a player can add Minor Consequence-like Aspects to an App.  Things like, "Slow Loading", "Glitchy", or "Bad User Interface".   Each Aspect adds +2 to the die roll when writing the App and when resetting the SOTA time.  These Aspects can be removed later with another Hacking roll, starting at Mediocre (+0) + the number of AMS used by the App (base time 24 hours).  [This is a variation of "Succeed at a Cost"]

3) Extra Time
In order to generate more shifts of success, a player can take more time to write the App, reset SOTA time, or remove Aspects.  Each step up the rung on the time ladder adds +1 to the die roll.  [This is a variation of "Succeed at a Cost"]

4) Once per Significant Milestone.
With the exception of removing the "Outdated" Aspect, a hacker can only work on a particular App once per Significant Milestone.