Action Initiative implements initiative similar to that of the Unearthed Arcana Greyhawk Initiative. Combatants declare actions in advance each turn; different actions use different combinations of die rolls to determine initiative position. Initiative goes from lowest to highest.
To facilitate this, users are presented with a dialog to select among various actions when rolling initiative. A filter dialog is presented to the GM when rolling for multiple combatants.
Settings are provided so the GM can choose different variants, including weapon damage, weapon type, and spell level. An advanced configuration allows the GM to define specific dice formula to use for each action, each spell level, and each weapon characteristic.
See the Github page for more details.