The APC 40 mkII is supported as of Live 9.1.3.
Third-party or modified MIDI Remote Scripts might not work anymore after auto updates: this article will help you sorting things out.
Find out here how to prevent natively supported MIDI controllers from being automatically configured as Control Surfaces.
Article explaining where a third-party Remote Script needs to be installed to get it working in Live.
Collection of information how to control Live via a mobile device
Learn the basics of connecting and integrating external hardware with Live.
This article explains what Control Surfaces are and how to configure both native and third-party scripts in Live.
Questions regarding Push's step sequencing behavior.
Questions and answers on how to control devices with Push.
Questions and answers regarding editing features in Push.