Voting for tags is a legacy feature, that was never added back to TPT when it was rewritten in c++. I honestly have no idea what voting for tags does, it may not have any purpose. I may look into it sometime, if it does have a purpose I could add the feature back to the official version.

The Android version is based off of my mod, which is based off of the original C version of TPT. It's actually a completely different codebase.

Edit: That feature works like magic :), it just lets moderators have another way to check whether a save is stolen. So if you copy save X, it will add to the save data some information about the username, saveid, title, description, and date of save X into your save. Moderators can view this to confirm a save was really stolen.