If you wan't to run code in any page, try uBlobeBM!
BlobeBM is an HTML program that runs bookmarklets in about:blank. It's very useful if bookmarklets don't work on your device or if they are blocked by your administrator. While the purpose of bookmarklets is lost in BlobeBM, (that is, being able to run code in any website) some bookmarklets are still useful and fun to mess with!
First, make sure that you allow popups on the page. This is because BlobeBM opens itself in about:blank. If the about:blank window opens, then it means that you have allowed popups, and can move on to the next step.
Where it says "Enter bookmarklet here", enter the bookmarklet code. Then click on the green "Add Bookmarklet" button.
It will prompt you for how you want it to be called. Name it something that makes sense, because once you have a long list of bookmarklets, you want it to be easy to tell which one's which.
Once you enter the name, you should see the bookmarklet show up. It consists of 4 buttons: The blue button is to run the bookmarklet, the remove button is to delete the bookmarklet, and the other 2 buttons are to rename the bookmarklet and edit the bookmarklet. Hovering over the blue button for a few seconds reveals the bookmarklet code.
You can add as many bookmarklets as you need onto BlobeBM. The bookmarklets will save even if you close the window or shut down your device.