A free program for Android, by Livingroom Workbench.
OctoApp is optimized for phone use but has a clean and user-friendly interface that makes it easy to navigate. In OctoApp, you can find all the options to get your OctoPrint printer working. Three workspaces are available in the application, and the first one is for connecting your printer. Once your printer is connected, you can start using the second one, the Prepare Workspace. Here, you can prepare for your print by heating the hotend, or by adjusting the bed level.
You can also control and tune your print by controlling the print temperature or by using advanced settings. You can also set the time and the amount of the print.
To make things easier, you can find all the necessary options in the menu in a single location.