I found this as a free download. You need to install .NET as well but it does an amazing job
Microsoft Research Image Composite Editor (ICE)
This extraordinary double rainbow at sunset is stitched from 4 Android phone photos using the software

 

I've been looking for something like this. Thanks for the link.

 

Works amazingly well with no manual fiddling required at all.

Both of these are 5 shots each.

 

I was amazed by the thing, as you say it just works.
Great photos BTW.

 

You can see the stitch points in the rainbow. I am a fine art photographer. The best stitching program is Photoshop. First do auto-aline Layers then follow with auto-blend Layers. The results are seamless.

 

Rich,
You can see the points because I moved position while taking the pictures.
Looking at the originals I was amazed that anything could have sorted them.
There is no stitching visible in Charlie's pictures.
The beauty of this package is that you just drop a directory of image files in and it sorts the whole thing.

 

I had just assumed that the cracked rainbow over Steve's house was...

Well err, a 'Steve' thing.

I'll give it a go.

Got to love an instruction found at the bottom of the page. "Click the Download button in the middle of this page".LOL

 

Rich, I will not deny that a Libation of RM to the God of the Rainbow MAY have caused some slight wobbliness.
There doesn't seem to be a software option 'Sort it out Even Though you're p*ss*d'

 

ICECUBES_V2 under development.

 

I like ICE, it has worked well for me.