I actually found a way to make the bookmarklets work. After naming and saving the javascript as a bookmark you go to the page you want to apply the bookmarklet to and in the browser's search box you start typing the name of the javascript bookmark until the browser shows the suggestion containing the link to it. Then you press enter and it's done!

Same problem here. I cannot get bookmarklets to work in Opera android. I'm trying to use the "save to Zotero" bookmarklet to work but, since I have to leave the page I want to save, the booklet has no effect. In Opera mini, the booklet seems to run but does not send the page either.