Yes, although certain capabilities will be limited or unavailable when the camera isn't locked down on a tripod.
Tripod-free shooting with a DSLR
On DSLRs, Arsenal offers a mirror-down AI mode for handheld shooting. In this mode, Arsenal constantly adjusts settings instead of changing them when you push the button on the app.
Since Arsenal doesn't have access to the live view data in Handheld Mode (the mirror is down, not up), some of the attributes it looks at when choosing settings are only updated after you press the shutter. If you move to a new location, you'll need to take a photo to update Arsenal's suggestions.
Tripod-free shooting with a Mirrorless camera
On Mirrorless cameras, there's a handsfree mode that does all of the AI calculations and continually updates settings.
Handheld mode can be entered by holding down the power button for 3 seconds, or from the app.
For more information on handheld shooting and its limitations, read the Introduction to Handheld Shooting.