When performing songs in a particular order, you should create a set list. The set that is currently shown/loaded on your device is always referred to as the 'current set'.
Songs can be added to sets by using various options on the song menu page or custom gestures.
Clicking on an item in the set menu will load that song. Swiping it left/right will remove it from the set and dragging up/down will allow you to reorder the set. You can also edit each item (to change the song folder/filename and key) by clicking on the edit button on the set item row.
Clicking on the + button in the set menu will give you additional options for your sets.
When viewing a song that is part of the current set, the song title in the action bar will show a 'tick'. You will also be able to see the next/previous songs in the set (assuming you have switched these on in the song display settings).
By default, the app will show an inline set on the left of the song display. You can switch this off or change the settings from the Inline set settings.
Additional set options:
Create a new set: Clear the current set ready to start again. This removes all items from your current set.
Manage your sets: Takes you to the set menu settings. Used to load, save, export, import set files. Current sets are only saved on the device, to allow other users to load your set, you need to save it as a set file.
Scripture: Insert a slide with scripture for presenting.
Custom slide: Insert a custom slide (text only, image slideshow, etc). Useful when projecting at the start of a service to display notices, etc. Custom notes can also be created to split your set up (e.g. Set 1, Set 2, etc.)
Find a random song: Similar feature to the random song button in the song menu, but this only chooses a random song from the current set.
Shuffle set: Randomise the order of your set items
Sort set: Sort your set alphabetically by item name