I was looking for a way to get the "read later" bookmarklet from Instapaper to work on my iPad because I like that one better than the built-in "reading list".
There's an easy fix to do this, but unfortunately it won't work for Safari since it doesn't let you edit the URL of the bookmark.
Now, because I use Chrome as the default browser on my iPad, I was able to add the "read later" bookmarklet without problems.
I listed the instructions below, but you can also check the entire article here (it also includes a lot of other sharing options to add to your browser).
1. Add the current page you're visiting as a bookmark
2. Edit the name of the bookmark to anything you like (e.g. Read later)
3. Replace the URL of the bookmark with the following line of code:
4. Save the bookmark, and you're done