Q: When do I press the start button?
A: As soon as you see the initial scoreboard when the game begins. Here's why, from MLG: http://www.mlgpro.com/Official_Halo_Reach_Game_Types
"The Rockets, Sniper, and Grenade Launcher are on drop spawns, allowing them to spawn on a constant timer. Due to the initial loadout screen, the timer begins 10 seconds before the game starts. Since it takes 2 seconds for a weapon to become “disturbed” from falling, the respawn timer has been adjusted to reflect that. If you pick the weapon up from mid-air, it could shorten the next respawn by 1-2 seconds. This means weapons can no longer be “dirtied” like Halo 3. The Sniper and Grenade Launcher are set to respawn every 118 seconds and the Rockets are set to respawn every 178 seconds." 
Q: Why is there only one button to start all three of the timers?
A: Weapon spawning works differently in MLG settings then normal Bungie settings. Weapons spawn at fixed times. For example, the sniper rifle spawns every 1:58 minutes. In a 15 minute game, it will respawn at 13:10, 11:10, 9:10, 7:10, 5:10, 3:10, 1:10 until the game ends. (But why isn't 13:10 + 1:58 = 15:00? Read the previous FAQ to find out!) Sniper and rockets both follow this pattern, thus both timers are synchronized within our app.

Slayer Mode FAQs
Q: I started a timer right when I picked up a weapon, but it didn't respawn when your app said it should. Why not?!
A: Some weapons have an extra constraint on their spawn called max count. (This property can be viewed in the Forge) For example the sword on Sword Base has a max count of 1, this prevents another sword from spawning while one is already out and in use by a player. Most weapons have a max count of 2. If two of a weapon are out, another will not spawn even if it's spawn time has elapsed.

General FAQs
Q: Can this app be used for normal Team Slayer Games?
A: Yes, we have created a Team Slayer mode! However, this feature is only available in the donate version of the app. If you like what we are doing with the app, or just simply want this feature, please consider the donate version.