The Vault wouldn't let me update my Simple Healer's Kit so here's another post. Totally redone, it uses a straight Heal skill check and gets rid of damaging the recipent on a natural 1 and double healing on a natural 20. Limits healing to 1d6, +1 per 5 ranks of the heal skill of the user (max +6).
Requires the use of tag-based OnItemActivate scripts for your mod. Original idea by Drakaden.