Remote Detonator

Effects

Activating the Remote Detonator will cause all bombs placed by Isaac to explode.
Bombs will no longer explode without the usage of the detonator.
Gives 5 bombs when picked up. If the item is picked up a second time in the same run, this effect will not be applied.

Remote Detonator gives Isaac five bombs for the price of three (using the bombs on the donation machine to trade for coins) when bought at a Shop, making its purchase a good value if the player is low on bombs.
Remote Detonator does not control the explosions of Troll Bombs and Mega troll bombs.
It does control throwable bombs spat out by Bomb Grimaces, once picked up. The bombs can be carried throughout rooms without ever exploding until Remote Detonator is used, making a Bomb Grimace essentially equivalent to a Golden Bomb with this item.
If Chub or Carrion Queen swallow a remote bomb, the bomb will be released from them after the animation unless it is detonated manually.

(Added in Repentance) (Bob's Bladder) Bob's Bladder: Undetonated bombs can be used to maximize creep damage.
Bobby-Bomb: Bombs placed will chase after the enemy, making it easier to do massive amounts of damage to enemies.
Book of Virtues: Summons wisps when bombs placed by Isaac explode. Using Remote Detonator also causes the wisps' tears to explode, dealing 16.5 damage to enemies that are close to them (24 if Isaac has BFFS!).
Curse of the Tower: The Troll Bombs generated upon taking damage will not explode until the Remote Detonator is used, unlike normal Troll Bombs.
Dr. Fetus: Remote Detonator can be used to detonate the fired bombs early, which can be useful against moving enemies.
Eye of Belial: Bombs can be shot to gain the full effect of the eye. Especially useful on bosses that do not spawn enemies.
Number Two: The bombs automatically dropped by No. 2 will not detonate on their own, greatly reducing the risk of accidental explosive self-damage.

Car Battery: No effect.
Scatter Bombs: Remote Detonator can be used on the original bomb, but not on the small bombs that are spawned.