Layer HDR or bracketed photos together

[vwvapor]

I use the WiFi on my digital camera to transfer directly to my Android device, but my digital camera does not have in camera HDR stitching so I'm stuck with 3-7 photos from HDR bracketing mode.

I see numerous HDR camera apps, but none seem to stitch photos unless they're taken with the phone/app.

Does anyone know of an app that can do this via Android?

Thanks!