Android : how to open Gallery inside the Application just like Facebook messenger ????

I saw that in Facebook messenger Chat room , when i do the chat with any person there is option for send the picture to that person , that time when i click on icon to browse the image from gallery then all the pictures comes at bottom , them i can slide from left to right and right to left .. and when i click on picture it automatically goes to person . Basically i am making Android app in which i want that user upload his/her picture from gallery , i used onActivityResult , but i want just like above . Thanks for your help .