Invincibility
Invincibility Mod — this addon will render you immune to all forms of damage while in survival mode. Once you install the Invincibility addon, you’ll be able to perform incredible feats that were previously impossible in Minecraft Pocket Edition. For instance, you can now swim in lava, leap from great heights, and take absolutely no damage at all. You essentially become invincible!
How Does It Work?
The player is not susceptible to various types of damage. Here are some examples:
Burning: walk through fire and swim in a pool of lava. It may seem unbelievable, but it’s true—you can make the impossible possible! Now you can engage in such daring acts without suffering any harm. Fire will no longer bring death your way. 
Drowning: dive underwater for as long as you like and enjoy the experience of swimming beneath the surface. This mod offers an amazing opportunity to explore underwater structures more thoroughly without the risk of drowning.
Mob Attacks: no mob can inflict any damage on you anymore. They will still attempt to attack, but they won’t be able to hurt you.
Fall Damage: now you can jump off high cliffs without taking any damage whatsoever.
Explosions: creepers are no longer a threat to you. While they can still destroy your structures, they cannot deal damage to you. 
Installing Invincibility (.mcpack)
- Download the mod marked with “.mcpack” below.
- Open the downloaded file to import the addon/texture into MCPE.
- Launch Minecraft Pocket Edition and go to world settings.
- Apply the imported:
— Add-on Packs to your world. - Select the imported addon.
- It is recommended to restart the game client Minecraft PE after this step.
- Start Minecraft Pocket Edition, enter the configured world MCPE, and enjoy the addon!
Installing Invincibility (.zip)
- Download the mod below.
- Extract the folder from the archive.
- Move the folder “deedubbs.invincibility.behaviour-0.0.1” to the /games/com.mojang/behavior_packs/ directory.
- Launch Minecraft Pocket Edition.
- Create a new world or edit an existing one.
- Apply the addon you moved earlier to the behavior_packs folder to the selected world.
- Done! Restart Minecraft PE and enjoy playing!