I've had this toolkit in my in my tool chest for years now, and it sees such frequent use that I absolutely recommend it. It has everything you need for operating on small electronics, from all the weird bit heads to a flexible neck extender, suction cups, tiny pincers, etc. If you've ever attempted any kind of device repair, you need something like this – but as far as I know, this is the best one, so just start here.
Buy it directly from iFixit.