What tools have people found useful/allowed to program into a polyhand?
You replace your entire hand with a hand made of reprogrammable microscopic adamantine prisms. With either a mental command or a programmable interface built into the hand, you can reconfigure your hand into the shape of various tools. The hand can contain programming for nine different tools, in addition to a configuration for a normal hand for your species. As a move action, you can switch the setting, causing the adamantine pieces to realign into the shape of the chosen tool. The tool has all the flexibility of the normal tool (or of a hand, if set to that).
Programming a new tool into the polyhand takes 10 minutes, and you must choose either to fill an empty slot or to replace a programmed tool. The tool replicated must be 8th level or lower. The polyhand can replicate the moving parts of a tool, but you must supply any fuel or batteries needed for the tool to function. The tool cannot produce substances, and since it’s not very conductive (important so as to avoid shocking the user), it can’t serve as a power conduit or data transmission line. The GM has final say in deciding which tools you can duplicate. The tools within engineering kits and similar kits can be duplicated, subject to the restrictions above.
You can clearly duplicate basic toolkits, but "tool" is a pretty broad category not given a game definition, and the 8th level and below limitation seems to envision allowing things more complex.
Here's some arguable "tools" that might be programmed into a multitool in addition to the standard skill toolkits necessary to use things like Computers (without an interface) or Engineering:
1. Glass Cutter (level 1-2 Personal Item from Armory): "This tool consists of..." Allows you to cut 1' diameter (or just make up something smaller for hand size limitations and repeat as needed) holes through glass thickness materials that have a hardness of 10 or less, including transparent aluminum.
2. Map (level 1 Personal Item from Armory): I'd allow you to program in an ultrathin, rigid bas relief/etched physical map that your hand flattens out to. Grants up to a +2 bonus for orienteering and navigation.
3. Tool, Manual (level 1 Personal Item from Armory): +1 circumstance bonus to relevant tasks/checks. You definitely want an adapted crowbar or wedge of some sort for breaking down doors if you fail your engineering check to bypass or if the thing is just stuck.
4. Tookit (level 1 technological item, Armory and Pact Worlds). Specific took kits have been mentioned that give +4 circumstance bonuses to various specific skill uses. Many of these are going to require GM negotiation on whether they have the sorts of nonpowered/nonexpendable components that your hand is capable of forming, but the Armory thieves tools (+4 to hack a door with Computers or bypass a door with Engineering) definitely should be the first item most polyhand owners program in. The Pact Worlds climbing kit, demolition kit, and starship repair kit might also be compatible with this item. (You'd have to reflavor a climbing kit as a hand grapple/claw rather than free standing rope and pitons.)
5. Manacles (level 4, tech item, Core): Need to frog march a prison immediately in front of you with his arms bound behind you, a pistol in your other hand? I see no reason this shouldn't work.
This item seems way too high level and expensive for what it can actually do right now.