Hello everyone! I am new to blenderartist, my name is kushiro 
I created an addon and I want to share with you.
It is called “Attach Align”. It can be used to move a geometry on top of another geometry, and also align the orientation easily!
It is free. Hope you enjoy it ! 
https://gumroad.com/l/iutJRq
Useful, thanks for sharing.
Thanks! If you have any suggestions or comment, please let me know 
Kushiro, which versions of blender does your addon work with? Thanks
Hi! I tested on both 2.83 and 2.9.
Kushiro,
Thank you very much for sharing. It is supper useful.
You are welcome!
New version 1.2 is released today!
Added new features!
Version 1.2:
Now work on object mode. It utilize blender’s “multiple object edit” in 2.8. You just have to select two objects, enter edit mode (yes, both objects will enter edit mode together), then select the first face from source object, and second face from target object, then Attach, it works! Also Align edge mode works too!
Added “edge slide” function. Now when you select only 1 edge then run it, it enter edge slide mode, you can move the cursor left and right to slide the source geometry
Enjoy 
It will be nice to match the normal rotation as well. If you have a rectangular faces from different angles selected.
Extremely helpful add-on! Thanks a lot!
Awesome , thank you 
just idea
This addon is sooo good, simple and useful! Thanks.
If I could add a suggestion it would be the option to use vertex selection to get a faster attachment to a corner, it would save some steps if you are looking to specifically do that.
Example: selecting 3 vertex on the faces you want to attach
They attach using the normals generated by the selection
I know it’s too late but if you still need it
