The machine sprite in the smartgun trick is a nice one that can give a technomancer or their buddy an edge in combat. It's not a game changer but it's certainly helpful. The relevant ingredients are the Diagnostics power on p. 242 of the core book. The sprite makes an assisting teamwork test with two times it's rating. Generally what I do especially at convention tables is I ask the GM when i put the sprite in the gun if I can make one roll then and have it stand for all the teamwork the sprite will do. The sprite will do a task for 8 hours which is good because an unregistered sprite will only stick around 8 hours anyway. The max number of dice you can recieve from this trick is equal to the performing character.
Now one important caveat to all this. If your using an unregistered sprite unless your keeping your icon present on the gun or other device then this is going to count as a remote service which forfeits any other services you might have from the sprite, so there's no retasking the sprite from one gun to the next without dismissing it and calling for another.
Other handy sprite tricks, normally i'm pretty dismissive of combat hacking feeling that even the lamest shot is better off shooting something to eat reaction dice (or better still directing drones to do so) however sprites are the exception to this one. In a protracted gun battle routing tacnet data to your sprite (GM's discretion on if you can do this or not) and telling it to search for, log onto, and crash the nodes of the biggest hostile you can find is a great way to rob people of smartlink/gun/tacnet bonuses. Alternatively if your not hacking someone mid combat but knowing you are going to get into combat with them hacking their cyberware (if they have it accesable from their comlink) not all will. Blinding them will typically not be really effective at my tables, they'll spend a simple action at best to reboot some devices or switch device modes on their personal eyes, but a silled enough hacker or sprite can selectively edit their input to make them miss or other things. Hackers/Technomancers are like faces and infiltrators in combat, they have to find their own opportunities and shape the battlefield, ideally before the shooting has even started.