Imagink for your iPhone/iPad manages up to 5 layers.
Select the layer menu in the right panel.
To add a new layer, simply tap on the + button.
To hide a layer, tap on the eye icon next to the layer you want to hide.
To move a layer, select and hold a layer and drag it up or down.
To delete a layer, click and hold the layer, drag it towards the red bin and release it.
To change the opacity of a layer, double click on the current opacity level and enter the new value.