There are 2 types of power-ups, there are battle power-ups and there are daily power-ups.
Battle power-ups can be used every time you are either attacking or defending against someone, and daily power-ups can be used by to increase the amount of Energy or Stamina you have.
Battle power-ups can be very useful. Do not underestimate the power of a battle power-up.
There are 2 types of battle power-ups: red (offensive) and green (defensive). The red ones are used when you are attacking an opponent, and the green ones are used when an opponent attacks you.
You must make sure that the power-ups you buy are activated, otherwise they will not be used. To activate a defensive power-up, go to the "My Squad" page and click on the power-up that you wish to activate. You will see the power-up have a green/white outline around it. To activate an offensive power-up, go to the "Battle" page and click on the power-up you wish to activate, the power-up will have a green/white outline around it to show it is active.
Here is a list of all the available power-ups in the game, as well as what level to unlock them. The price of each power-up varies in both cash and gold bar form (yes, some of them cost gold bars).
Attack Dog - +10 to Attack - Available at Level 10
Frag Grenade - +30 to Damage - Available at Level 15
UAV Detection - +50 to Attack - Available at Level 30
C4 Breaching Charge - +30 to Damage - Available at Level 45
Gunship Barrage - +25% to Equipment - Available at Level 65
Laser Guided Missile - +100 Damage - Available at Level 100
Napalm Strike - +75% to Equipment - Available at Level 135
Nuclear Attack - -50% to Enemy Tactics - Available at Level 140
Stopping Power Ammo - +5 to Damage - Available at Level 15
Flak Jacket - +25 to Defense - Available at Level 20
Sentry Gun - +80 to Defense - Available at Level 40
Claymore Mine - +30 to Damage - Available at Level 45
Helicopter Minigun - +25% to Equipment - Available at Level 65
Tactical Operations Center - +100 to Damage - Available at Level 100
Fire Support Base - +75% to Equipment - Available at Level 135
Anti-Missile Defense System - -50% to Enemy Tactics - Available at Level 140
Daily power-ups can actually be used every 18 hours, so if you time it correctly and can live with just 6 hours of sleep every once in a while, you can actually get away with using a daily power-up every 18 hours!
There are 2 types of daily power-ups, energy drinks and stamina bars, and you can only use one of them once every 18 hours, regardless of the type that you choose.
There are 4 sizes of energy drinks:
There are 2 sizes of stamina bars:
The great part about these daily power-ups is that you can use them at any level! The only down-side to being able to use them all is that the game limits the full amount of energy, you will only get a percentage of it depending on what level you are.
Don't forget to send power-ups out to people! Even if you cannot offer monster sized power-ups, send the largest size that you can of either power-up: it's the thought that counts!