The armor stand is an official feature in the PC version for Minecraft. Right now it’s only accessible for Minecraft Pocket Edition users by getting a mod like this one. It adds one new item to the game which can be used for spawning the armor stand entity. Armor stands are the best way to store your armor since you are likely to forget about them if you use chests.
How to use?
Find the armor stand item in your creative inventory. The item icon looks like a pressure plate. Place down the armor stand on the ground. (Make sure you’ve set difficulty to max. Otherwise there’s a possibility it won’t work.)
Most of the time it will spawn empty. Tap on the armor stand with armor items to add them to the stand.
The armor stand can be used to display any type of armor set, even mixed ones.
You can add mannequins (zombie/player) to an armor stand. Tap on it with an empty hand to open the menu.
Important: This mod requires BlockLauncher which is a third-party app for Minecraft PE.