Nimble Launcher is a lightweight launcher which uses advance algorithm to learn from your habits. Nimble launcher is designed to make your actions quicker while using very low limited resources.
https://play.google.com/store/apps/details?id=ritik.launcher
⇒ Quick Access Home Screen
⇒ Small Size
⇒ Low Ram requirements
⇒ Save Battery
⇒ Search for anything right from your homescreen
Source Code of Nimble Launcher can be found at https://github.com/ritikchanna/NimbleLauncher
Also try the amazing KISS Launcher https://play.google.com/store/apps/details?id=fr.neamar.kiss